Co-reporter:Chenglong Zhao, Hongfang Zhang, Jianbin Zheng
Journal of Electroanalytical Chemistry 2017 Volume 784() pp:55-61
Publication Date(Web):1 January 2017
DOI:10.1016/j.jelechem.2016.12.005
•Ag/boehmite nanotubes/rGO was synthesized by employing boehmite nanotubes/rGO as catalyst support.•It was the first demonstration of fabricating the H2O2 sensor based on Ag/boehmite nanotubes/rGO nanocomposites.•This sensor exhibits excellent catalytic performance for hydrogen peroxide detection.The Ag/boehmite nanotubes/reduced graphene oxide nanocomposites (Ag/boehmite nanotubes/rGO) have been synthesized for enhanced electrochemical sensing of hydrogen peroxide (H2O2). Field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and X-ray diffraction spectroscopy (XRD) were applied to characterize the composition and morphology of the nanocomposites. TEM and FESEM images revealed that a great deal of Ag nanoparticles with spherical morphologies were fixed on the surface of boehmite nanotubes/rGO. The sensor based on Ag/boehmite nanotubes/rGO nanocomposites possessed remarkable performance for the electrical reduction of H2O2. and showed a linear response for the detection of H2O2 in the range of 0.5 μM–10.0 mM with a low detection limit of 0.17 μM (S/N = 3) and a sensitivity of 80.1 μA mM− 1 cm− 2. Besides, the as-prepared sensor exhibited outstanding anti-interference capability. Therefore, the excellent experimental results indicated that Ag/boehmite nanotubes/rGO nanocomposites is a promising type of support material for electrochemical detection of H2O2.
Co-reporter:Wushuang Bai, Xinjin Zhang, Sai Zhang, Qinglin Sheng, Jianbin Zheng
Sensors and Actuators B: Chemical 2017 Volume 242() pp:718-727
Publication Date(Web):April 2017
DOI:10.1016/j.snb.2016.11.125
•MnO2 nanoflowers were synthesized by one-step method.•Acidification of MnO2 was performed to modify its catalytic reactive and active crystalline facets.•H2O2 electrochemical sensor was fabricated based on acidized MnO2 to detect H2O2 released from living cancer and normal cells.•The obtained sensor exhibited remarkable catalytic performance for H2O2 detection.Nanomaterials have been used widely for electrochemical analysis in biological system in recent years. In order to cover the shortage of singular materials, composite nanomaterials were provided, but in the meanwhile laborious synthetic procedures and complex analytic mechanism has to be faced. In this work, for the first time, one-step acidification of flower-like manganese dioxide (MnO2) was performed to modify its catalytic reactive and active crystalline facets, and nonenzymatic electrochemical sensor was fabricated based on the singular materials to detect hydrogen peroxide (H2O2) released from living cancer and normal cells. According to the SEM, XRD characterizations and electrochemical investigations, it was found that 001 and 002 facets probably be the reactive facets while 111 and 020 facets are active facets. Meanwhile, the obtained sensor exhibited a low detection limit of 0.02 μM, a fast response and a wide linear range of 0.00008-12.78 mM which can be applied successfully for quantitative detection of H2O2 released from living cells in stimulation of AA. The work provides a simple and efficient electrochemical biosensing platform based on modification of crystalline facets of metal oxide. Considering the good sensing property, simple catalyst synthesis and analytic mechanism, its potential uses can be exploited for analytic, catalytic, physiological and pathological studies.
Co-reporter:Yu Shen;Dejiang Rao;Qinglin Sheng;Jianbin Zheng
Microchimica Acta 2017 Volume 184( Issue 9) pp:3591-3601
Publication Date(Web):29 June 2017
DOI:10.1007/s00604-017-2392-z
The authors describe a method to anchor gold nanoparticles (AuNPs) on carboxy-functionalized multi-walled carbon nanotubes (c-MWCNTs) utilizing chitosan as dispersing and protective agent. A sensor for the simultaneous determination of hydroquinone and catechol was then fabricated by placing this nanocomposite on a glassy carbon electrode (GCE). The morphology and composition of the nanocomposites were characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy and X-ray powder diffraction. The electrochemical behavior of the modified GCE was studied by electrochemical impedance spectroscopy, cyclic voltammetry and differential pulse voltammetry. The modified GCE exhibits good electrooxidative activity towards hydroquinone and catechol and therefore was used for simultaneous determination of both, with typical voltages of 30 and 130 mV (vs. SCE). A linear reponse is found for the 0.5 μM to 1.5 mM hydroquinone concentration range, and for the 5.0 μM to 0.9 mM catechol concentration range. The respective lower detection limits are 0.17 and 0.89 μM (at an S/N ratio of 3). The sensitivity is 644.44 μA mM−1 cm−2 for hydroquinone and 770.98 μA mM−1 cm−2 for catechol.
Co-reporter:Ning Zhang;Jianbin Zheng
Journal of Materials Science: Materials in Electronics 2017 Volume 28( Issue 15) pp:11209-11216
Publication Date(Web):19 April 2017
DOI:10.1007/s10854-017-6909-3
Ag–Fe2O3–RGO nanocomposites were successfully synthesized via hydrothermal and chemical reduction method. Based on this nanocomposite, a novel non-enzymatic hydrogen peroxide sensor was fabricated. Field emission scanning electron microscopy, X-ray diffraction spectroscopy, Transmission electron microscopic, Energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy were used for characterization of the nanocomposites, which proved that Ag NPs were well dispersed on Fe2O3–RGO. Electrochemical investigations indicated that the obtained Ag–Fe2O3–RGO nanocomposites had excellent electrocatalytic performance toward H2O2 reduction. The linear range for H2O2 was estimated to be from 1.6 × 10−6 to 5.7 × 10−2 mol L−1 with a sensitivity of 50.8 μA mM−1 cm−2 and a detection limit of 0.5 μmol L−1 (S/N = 3).
Co-reporter:Ziyin Yang, Sai Zhang, Yanyi Fu, Xiaohui Zheng, Jianbin Zheng
Electrochimica Acta 2017 Volume 255(Volume 255) pp:
Publication Date(Web):20 November 2017
DOI:10.1016/j.electacta.2017.09.160
•A facile hydrothermal approach is developed for the shape-controlled synthesis of CuCo2S4 by just changing the type of metal precursor without using template, structure-directing agent or complicated steps.•For the first time, CuCo2S4 was explored as electrocatalyst for H2O2 oxidation.•The sensor based on flower-like CuCo2S4 exhibited remarkable catalytic performance for H2O2 detection with a wide linear range, a high sensitivity and a low detection limit.Controllable synthesis of CuCo2S4 was reported for electrochemical sensing of H2O2. It is the first time that CuCo2S4 was explored as electrocatalyst for H2O2 oxidation. A facile hydrothermal approach is developed for the shape-controlled synthesis of CuCo2S4 by just changing the type of metal precursor. The structures, compositions and electrochemical properties of CuCo2S4 were studied. Electrochemical studies showed that flower-like CuCo2S4 with large surface area and three-dimensional porous structure exhibited excellent electrocatalytic activity toward H2O2 oxidation and an excellent analytical performances with a high sensitivity of 857.1 μA mM−1 cm−2, a low detection limit of 0.084 μM (S/N = 3) and a wide linear range of 4 orders of magnitude were achieved. These results demonstrated that CuCo2S4 was a promising efficient sensing material for electrochemical sensing of H2O2.
Co-reporter:Yu Shen;Jian Zhang;Qinglin Sheng;Jianbin Zheng
Chinese Journal of Chemistry 2017 Volume 35(Issue 8) pp:1317-1321
Publication Date(Web):2017/08/01
DOI:10.1002/cjoc.201600892
A novel non-enzymatic nitrite sensor was fabricated by immobilizing MnOOH-PANI nanocomposites on a gold electrode (Au electrode). The morphology and composition of the nanocomposites were investigated by transmission electron microscopy (TEM) and Fourier transform infrared spectrum (FTIR). The electrochemical results showed that the sensor possessed excellent electrocatalytic ability for NO2− oxidation. The sensor displayed a linear range from 3.0 μmol•L−1 to 76.0 mmol•L−1 with a detection limit of 0.9 μmol•L−1 (S/N = 3), a sensitivity of 132.2 μA•L•mol−1•cm−2 and a response time of 3 s. Furthermore, the sensor showed good reproducibility and long-term stability. It is expected that the MnOOH-PANI nanocomposites could be applied for more active sensors and used in practice for nitrite sensing.
Co-reporter:Chenglong Zhao;Hongfang Zhang
Journal of Materials Science: Materials in Electronics 2017 Volume 28( Issue 19) pp:14369-14376
Publication Date(Web):07 June 2017
DOI:10.1007/s10854-017-7297-4
The sea urchin-like Ag/FeOOH nanocomposites were prepared by a simple method, and a new enzymeless hydrogen peroxide (H2O2) sensor was fabricated by fixing Ag/FeOOH on a gold (Au) electrode. X-ray diffraction spectroscopy field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy were employed to study the composition and morphology of Ag/FeOOH. TEM and FESEM images revealed that a great deal of Ag nanoparticles with spherical morphologies were fixed on the surface of sea urchin-like FeOOH. The electrochemical investigations indicated that the Ag/FeOOH nanocomposites possessed remarkable capability for the electricalreduction of H2O2 and showed a linear response for the detection of H2O2 in the range of 0.03–15.0 mM with a detection limit of 1.3 μM (S/N = 3). Future, this sensor exhibited acceptable reproducibility and good anti-interference ability.
Co-reporter:Ziyin Yang;Qinglin Sheng;Sai Zhang;Xiaohui Zheng;Jianbin Zheng
Microchimica Acta 2017 Volume 184( Issue 7) pp:2219-2226
Publication Date(Web):06 April 2017
DOI:10.1007/s00604-017-2197-0
The authors describe the synthesis of a nanocomposite consisting of Fe3O4 nanoparticles, polypyrrole and graphene oxide (Fe3O4/PPy/GO), and its application to voltammetric sensing of hydrazine. The nanocomposite can be synthesized by combining chemical oxidative polymerization and co-precipitation. Fe(III) ion is employed as both the oxidant for pyrrole and as a precursor of Fe3O4. The nanocomposite was characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). TEM observations revealed that large numbers of Fe3O4 are homogeneously and densely distributed. The Fe3O4/PPy/GO composite was placed in a glassy carbon electrode, and the resulting sensor, best operated at around 0.2 V (vs. SCE) exhibited excellent response to dissolved hydrazine over the 5.0 μM to 1.3 mM concentration range, a sensitivity of 449.7 μA mM−1 cm−2 and a low detection limit of 1.4 μM (at an S/N ratio of 3).
Co-reporter:Ziyin Yang, Xiaohui Zheng, Jianbin Zheng
Chemical Engineering Journal 2017 Volume 327(Volume 327) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.cej.2017.06.120
•Au@Pt-nFs/GO was synthesized through a facile and green one-pot method.•Au@Pt-nFs/GO exhibit open structure with large surface area and abundant active site.•Au@Pt-nFs/GO was employed to fabricate nonenzymatic N2H4 sensor.•Au@Pt-nFs/GO reduced the overpotential and accelerated kinetics of N2H4 oxidation.•Au@Pt-nFs/GO exhibit highly sensitive and selective detection of N2H4.A novel strategy is developed to synthesize three-dimensional porous Au@Pt core-shell nanoflowers supported on GO (Au@Pt-nFs/GO) for enhanced electrochemical sensing of hydrazine (N2H4). Au@Pt-nFs/GO nanocomposite was synthesized through a facile and green method, where ascorbic acid and chitosan were employed as the reductant and linking agent, respectively. The experiment results revealed that a large numbers of Au@Pt-nFs with Au cores and Pt dendritic shells were distributed on the surface of GO sheets. Meanwhile, Au@Pt-nFs/GO with large surface area, abundant active sites and open structure reduced the overpotential and accelerated kinetics of N2H4 oxidation, therefore making the sensor based on Au@Pt-nFs/GO exhibit an excellent performance for N2H4 analysis with a wide linear range of 0.8 μM–0.429 mM, a high sensitivity of 1695.3 μA mM−1 cm−2 and a low detection limit of 0.43 μM (S/N = 3). Moreover, the sensor also exhibited good selectivity, repeatability and stability. Application of the sensor for the detection of N2H4 in tap water samples was demonstrated.
Co-reporter:Ziyin Yang, Xiaohui Zheng, Jianbin Zheng
Sensors and Actuators B: Chemical 2017 Volume 253(Volume 253) pp:
Publication Date(Web):1 December 2017
DOI:10.1016/j.snb.2017.06.112
•Porous MnCo2S4 sphere was synthesized through a facile hydrothermal method.•Porous MnCo2S4 sphere with a three-dimensional porous structure was constructed from interconnected nanoparticle.•For the first time, noble-metal-free MnCo2S4 was used as an excellent electrocatalyst for N2H4 oxidation.•The sensor based on MnCo2S4 exhibited remarkable catalytic performance for N2H4 detection.It is highly attractive to design and construct a novel enzyme-free electrode for sensitive and selective detection of hydrazine (N2H4). In this paper, for the first time, porous MnCo2S4 sphere was used as an excellent electrocatalyst for N2H4 oxidation, which was synthesized through a facile hydrothermal method. The experiment results revealed that porous MnCo2S4 sphere was constructed from interconnected nanoparticle with a three-dimensional porous structure. Electrochemical measurements demonstrate that the presence of MnCo2S4 reduced the overpotential and accelerated kinetics of N2H4 oxidation. The sensor based on porous MnCo2S4 sphere exhibited an excellent performance for N2H4 analysis with a wide linear range of 0.5 μM–4.78 mM, a high sensitivity of 1495.7 μA mM−1 cm−2, a low detection limit of 0.33 μM (S/N = 3). Moreover, the application of the sensor for detection of N2H4 in tap water samples was demonstrated, which indicates that MnCo2S4 can be employed as the efficient material for electrochemical sensing of N2H4.
Co-reporter:Ni Zhang, Zhongxi Li, Jianbin Zheng, Xiaoming Yang, Kun Shen, Tuankun Zhou, Ying Zhang
Microchemical Journal 2017 Volume 134(Volume 134) pp:
Publication Date(Web):1 September 2017
DOI:10.1016/j.microc.2017.05.006
•The novel dry ashing device based on infrared lightwave radiation is proposed.•The gold-plated layer of heating tube focuses infrared lightwave and strengthens sample ashing.•The flow-through ashing tube accelerates ashing. Carbonization and ashing are completed by the same device.•The device has a faster ashing speed, a smaller size than traditional devices.•The semi-open structure has the potential as a heating module of a fully automated ashing sample preparation system.A novel dry ashing method based on focused infrared lightwave ashing (FILA) was proposed for preparation of botanical samples enriched organic matter. High performance infrared quartz tubes were used in dry ashing devices as heating elements for the first time. A layer of gold was plated on the surface of the heating tube in order to reflect and focus infrared light and enhance the effect of heating. Meanwhile, the self-designed flow-through quartz ashing tube ensures oxygen to penetrate the entire sample layer, thus increasing the efficiency of sample ashing. In addition, the heating chamber has a very small space and the size of the proposed device is only one-fifth of a traditional muffle furnace's size. The sample can be quickly heated from room temperature to 900 °C just in 1 min. For most kinds of samples, ashing can be completed within half an hour. After the ash was dissolved with diluted nitric acid, multielements were determined in the solution by inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. Five certified reference materials of plants were used as examples to demonstrate the performance of the developed device. The agreement to the certified values was between 80 and 114% for Be, Na, Mg, P, K, Ca, Mn, Co, Ni, Cu, Zn, Rb, Sr, Mo, Cs, Ba, Pb, Bi, Th, U and rare earth elements. Moreover, the FILA system was also applied to the analysis of five real botanical samples. The results showed no significant difference from the ones by microwave digestion (MW).Download high-res image (118KB)Download full-size image
Co-reporter:Ziyin Yang, Xiaohui Zheng, Jianbin Zheng
Journal of Alloys and Compounds 2017 Volume 709(Volume 709) pp:
Publication Date(Web):30 June 2017
DOI:10.1016/j.jallcom.2017.03.201
•Fe2O3/N-rGO was synthesized through a facile one-step hydrothermal method.•Ethylenediamine was used as reducing agent, nitrogen source and coordinating agent.•Fe2O3/N-rGO was employed to fabricate a novel non-enzymatic sensor.•The sensor exhibits remarkable catalytic performance for dopamine detection.Fe2O3/nitrogen-doped reduced graphene oxide (Fe2O3/N-rGO) was synthesized for enhanced electrochemical determination of dopamine (DA). The nanocomposite was synthesized through a facile one-step hydrothermal method, where ethylenediamine served as reducing agent, nitrogen source and coordinating agent, therefore making the reduction and nitrogen doping of GO and the formation of Fe2O3 occur simultaneously. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction spectroscopy (XRD), fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and electrochemical techniques were employed to characterize Fe2O3/N-rGO. The results showed that large numbers of Fe2O3 with spindle morphology were distributed on the surface of N-rGO and the synergetic effect between Fe2O3 and N-rGO made the sensor based on Fe2O3/N-rGO exhibit an excellent performance toward DA detection with a wide linear range of 0.5 μM to 0.34 mM, a high sensitivity of 418.6 μA mM−1 cm−2 and a low detection limit of 0.49 μM (S/N = 3). Moreover, the sensor also exhibited good selectivity, reproducibility and stability. Therefore, Fe2O3/N-rGO can be applied as a promising type of sensing material for electrochemical detection of DA.A facile one-step hydrothermal method was reported to synthesize Fe2O3/N-rGO for enhanced electrochemical determination of dopamine.Download high-res image (187KB)Download full-size image
Co-reporter:Jinqiong Xu, Qinglin Sheng, Yu Shen, Jianbin Zheng
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2017 Volume 529(Volume 529) pp:
Publication Date(Web):20 September 2017
DOI:10.1016/j.colsurfa.2017.05.049
•Gold nanoprisms–chitosan composite film as immobilizing matrix realized the direct electrochemistry of glucose oxidase.•Gold nanoprisms accelerated the direct electron transfer rate between glucose oxidase and the substrate electrode.•The GOD–Gold nanoprisms–chitosan composite film modified electrode was successfully applied in glucose detection.Gold nanoprism (AuNP) was used for immobilization of glucose oxidase (GOD), and the direct electrochemistry of GOD–AuNP–chitosan modified GCE and glucose biosensing were studied. Transmission electron microscopy, UV–vis spectroscopy and electrochemical impendence spectroscopy were employed to confirm the morphology and film modification changes of the prepared biosensor. Results showed that the AuNP can provide a favorable and biocompatible microenvironment for facilitating the direct electron transfer between proteins and electrode surface. It was found that the special structure of gold nanoprism exhibited enhanced performances in direct electron transfer of GOD and glucose sensing. The adsorbed GOD displayed an apparent electron transfer rate constant (ks) of 24.92 s−1. The constructed biosensor exhibited a good response to glucose with linear range from 0.05 to 1.2 mM (R2 = 0.9975), low detection limit of 0.01 mM and high sensitivity of 11.83 μA mM−1 cm−2. The proposed biosensor offers an alternative method for the determination of glucose in real samples and has potential applications in the fabrication of other biosensors with redox proteins.A pair of distinct and well-defined redox peaks is observed at the GOD–AuNP–chitosan/GCE (curve c) with the formal potential of −0.460 V (vs. SCE) and the peak to peak separation was 52 mV.Download high-res image (103KB)Download full-size image
Co-reporter:Huan Hao, Qinglin Sheng, Jianbin Zheng
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2017 Volume 518(Volume 518) pp:
Publication Date(Web):5 April 2017
DOI:10.1016/j.colsurfa.2017.01.027
•Ag@SiO2@Ag core-shell structure nanomaterial was synthesized by a simple one-step method.•The core-shell structure Ag@SiO2@Ag nanomaterial has a uniform size and AgNPs were distributed on the surface of Ag@SiO2.•The new sensor exhibited good electrocatalytic activities toward H2O2 reduction with wide linear range and high sensitivity.Ag@SiO2@Ag core-shell structure nanomaterial was synthesized by a simple one-step method, and applied to electrochemical sensing detection of H2O2. The results of transmission electron microscope (TEM), X-ray diffraction (XRD) and energy dispersive spectrometry (EDS) verified the morphology, structure and composition of Ag@SiO2@Ag nanomaterial. The current response of the Ag@SiO2@Ag sensor was linearly toward to concentration of H2O2 between 0.005 mM and 24.0 mM with a detection limit of 1.7 μM at a signal-to-noise ratio of 3. The sensitivity was 56.07 μA mM−1 cm−2. The Ag@SiO2@Ag/GCE exhibited wide linear range and high sensitivity for electrochemical detection of H2O2.Ag@SiO2@Agcore-shellstructurenanomaterialwassynthesizedbyasimpleone-stepmethod.(*) The H2O2 electrochemical sensor was fabricated by immobilizing Ag@SiO2@Ag nanomaterial on GCE. The electrochemical investigations for this sensor exhibited excellent sensing properties.Download high-res image (110KB)Download full-size image
Co-reporter:Sai Zhang;Yanyi Fu;Qinglin Sheng;Jianbin Zheng
New Journal of Chemistry (1998-Present) 2017 vol. 41(Issue 21) pp:13076-13084
Publication Date(Web):2017/10/24
DOI:10.1039/C7NJ01835E
Nickel–cobalt layered double hydroxides (NiCo-LDHs) were synthesized using a facile hydrothermal method and then wrapped around amorphous Ni(OH)2 nanoboxes with intact shell structures. The morphology and shape of the Ni(OH)2/NiCo-LDHs nanocomposites were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and X-ray diffraction (XRD). Cyclic voltammetry (CV) was used to evaluate the electrochemical performance of the Ni(OH)2/NiCo nanocomposites modified electrode towards dopamine. With a potential of 0.22 V, the Ni(OH)2/NiCo-LDHs modified electrode was used to determine dopamine by amperometry, showing a significant current response and a linear dependence (R = 0.9997) in the concentration up to 1.08 mM with a sensitivity of 83.48 μA mM−1 cm−2 and a low detection limit of 17 nM (signal-to-noise ratio of 3). In particular, the fabricated dopamine sensor showed excellent reproducibility, long-term stability and favorable anti-interference.
Co-reporter:Qinglin Sheng;Yu Shen;Jian Zhang;Jianbin Zheng
Analytical Methods (2009-Present) 2017 vol. 9(Issue 1) pp:163-169
Publication Date(Web):2016/12/22
DOI:10.1039/C6AY02196D
In this work, attractive core–shell structured nanomaterials consisting of Ni doped Ag@C were synthesized. Further, a hydrogen peroxide (H2O2) sensor was fabricated by modifying the Ni doped Ag@C (Ni/Ag@C) nanocomposites onto the surface of a glassy carbon electrode (GCE). The composition and morphology of the Ni/Ag@C nanocomposites were characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. The results indicated that the nanocomposites were synthesized successfully and showed similar grain sizes and favorable dispersity. The electrochemical and electrocatalytic properties of the Ni/Ag@C nanocomposites were studied by cyclic voltammetry. An electrochemical investigation showed that the Ni/Ag@C nanocomposite modified GCE exhibited a good electrocatalytic ability for H2O2 reduction and it was used for the determination of H2O2. The linear range for H2O2 determination was from 0.03 mM to 17.0 mM with a detection limit of 0.01 mM (S/N = 3). The sensitivity was 22.94 μA mM−1 cm−2. It is expected that the application of the Ni/Ag@C nanocomposites could be extended to the construction of other sensors and applications in various sensing fields.
Co-reporter:Yanyi Fu;Qinglin Sheng;Jianbin Zheng
Analytical Methods (2009-Present) 2017 vol. 9(Issue 19) pp:2812-2820
Publication Date(Web):2017/05/18
DOI:10.1039/C7AY00090A
Au nanoparticles supported on nickel hydroxide nanowires with multiple cavities (Au/m-Ni(OH)2) were synthesized and used for the enhanced electrochemical sensing of dopamine (DA). m-Ni(OH)2 nanowires were first fabricated based on an anion exchange strategy and then chosen as supports for Au nanoparticles without an additional stabilizer and surfactant. The morphology and composition of the nanocomposites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). TEM observations revealed that Au nanoparticles were uniformly embedded in the cavities of m-Ni(OH)2 nanowires, with a high dispersion and a narrow size of 2 nm. Electrochemical investigations indicated that the as-prepared sensor exhibited fascinating performance towards the oxidation of DA. The linear range for DA detection was 0.45 μM to 1.78 mM with a low detection limit of 0.09 μM (S/N = 3). Additionally, the DA sensor possessed an excellent selectivity in the presence of potentially interfering substances such as ascorbic acid (AA), uric acid (UA) and glucose (Glu). Therefore, it is expected that Au/m-Ni(OH)2 nanocomposites could be used as electroactive materials for developing DA sensors.
Co-reporter:Yu Shen;Qinglin Sheng;Jianbin Zheng
Analytical Methods (2009-Present) 2017 vol. 9(Issue 31) pp:4566-4573
Publication Date(Web):2017/08/10
DOI:10.1039/C7AY00717E
A nanocomposite of platinum–nickel bimetallic decorated poly(dopamine)-functionalized reduced graphene oxide (Pt–Ni/PDA/rGO) was prepared by a facile and attractive method. Furthermore, a high-performance electrochemical sensor for the detection of dopamine was fabricated by dropping the Pt–Ni/PDA/rGO nanocomposites on a glassy carbon electrode. The morphology and composition of the Pt–Ni/PDA/rGO nanocomposites were characterized by field emission-scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, energy-dispersive X-ray spectroscopy, Raman microscopy and X-ray photoelectron spectroscopy. Electrochemical impedance spectroscopy, cyclic voltammetry and chronoamperometry were used to investigate the electrochemical behavior of the Pt–Ni/PDA/rGO nanocomposites. The linear range and detection limit were 0.2–911 μM and 0.07 μM, respectively. The sensitivity of this non-enzymatic dopamine sensor was calculated to be 912.8 μA mM−1 cm−2. Moreover, the Pt–Ni/PDA/rGO nanocomposite-modified GCE also showed good anti-interference ability and stability.
Co-reporter:Yanyi Fu;Qinglin Sheng;Jianbin Zheng
New Journal of Chemistry (1998-Present) 2017 vol. 41(Issue 24) pp:15439-15446
Publication Date(Web):2017/12/04
DOI:10.1039/C7NJ03086J
Herein, a novel dopamine (DA) electrochemical sensor was developed by combining carbon nanospheres (CNSs) and sulfonated polyaniline (SPANI) with their own excellent characteristics. The sensing materials SPANI/CNSs were prepared through a green and economical approach under hydrothermal treatment, in situ chemical oxidative polymerization, and sulfonation. Scanning electron microscopy and Fourier transform infrared spectroscopy were employed to characterize the morphology and composition of the nanocomposites. Moreover, electrochemical activities of the sensor were investigated by cyclic voltammetry, differential pulse voltammetry, and amperometry. Investigation of the sensor indicated that it had excellent properties towards DA oxidation, with a linear range from 0.50 μM to 1.78 mM, a detection limit of 0.0152 μM (S/N = 3), and a sensitivity of 113.9 μA mM−1 cm−2. Moreover, the sensor exhibited intriguing anti-interference to co-existing substances such as ascorbic acid (AA), uric acid (UA), and glucose (Glu). These electrochemical results could be attributed to the enhanced electron transfer rates and abundant functional groups with negative charges possessed by the nanocomposites. Therefore, the SPANI/CNS nanocomposites showed great application potential for the construction of a DA sensor.
Co-reporter:Jianbo Liu, Minyan Zheng, Ping Zhang, Yonghui Shang, Jianbin Zheng, Wushuang Bai
Journal of Electroanalytical Chemistry 2017 Volume 799(Volume 799) pp:
Publication Date(Web):15 August 2017
DOI:10.1016/j.jelechem.2017.06.016
•The nanocomposite of cobalt nanoflowers on graphene was synthesized by a facile electrochemical method.•Using nanocomposite and protein conformational intermediate, a novel biosensor was structured.•The biosensor exhibited accelerated direct electron transfer and showed high sensitivity.The nanocomposite of cobalt nanoflowers on graphene (Co-GE) was synthesized by a facile, one-pot ultrasonic electrochemical method. The scanning electron microscopy measurements displayed that the synthesized Co-GE exhibited a related hierarchical structure of a flake GE homogeneous distribution as a matrix for the growth of Co nanoflowers. The chemical composition was confirmed by energy dispersive X-ray spectrograms and X-ray diffraction analysis. The electrochemical biosensors based on redox proteins or enzymes possess high selectivity and biological compatibility but suffer from the low voltammetric response due to the deep burial of electroactive center in proteins. Herein, two typical denaturants, urea and acid, were synergistically utilized to maintain hemoglobin (Hb) in its most unfolded state, while simultaneously maintaining the presence of the heme groups. A novel hydrogen peroxide (H2O2) biosensor was structured using nanocomposite and protein conformational intermediate. The unfolded Hb/Co-GE/GCE exhibited accelerated direct electron transfer for sensing H2O2 under optimal conditions. The sensitivity for detecting H2O2 improved as much as 8.3 times higher than those for the native Hb/Co-GE/GCE. The electrocatalytic reduction of H2O2 showed a wide linear range from 0.25 to 190.0 μM with a high sensitivity of 116.3 μA mM− 1 and a low limit of detection of 0.08 μM (S/N = 3). The unfolded Hb-based biosensor possesses the advantages of excellent stability, good reproducibility, and satisfactory recovery. The current research provides a novel strategy to utilize the unique properties of protein conformational intermediates in the development of electrochemical biosensors.The peak current of uHb/Co-GE/GCE is much greater than that of Hb/Co-GE/GCE, suggesting that the greater exposure of the electroactive center and the change of Hb conformation. The entrapped Hb in uHb/Co-GE/GCE is controlled to the most unfolding state, and the electrocatalytic ability of Hb/Co-GE/GCE is extremely improved.Download high-res image (162KB)Download full-size image
Co-reporter:Huan Hao;Qinglin Sheng;Jianbin Zheng
Chemical Papers 2017 Volume 71( Issue 3) pp:535-542
Publication Date(Web):2017 March
DOI:10.1007/s11696-016-0001-y
Ag@C core–shell structure composites were successfully synthesized by hydrothermal method, and then Ag nanoparticles were decorated on the surface of Ag@C by reduction of AgNO3. The morphology, composition and structure of the Ag@C@Ag composites were characterized by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). Cyclic voltammetry and amperometry were used to evaluate the electrocatalytic performance of the Ag@C@Ag/GCE for detection of H2O2. Meanwhile, a new electrochemical method of zero current potentiometry was used for electrochemical detection of H2O2. The linear range and the detection limit were from 0.2 to 10, and 0.07 μM, respectively.
Co-reporter:Yu Shen, Dejiang Rao, Wushuang Bai, Qinglin Sheng, Jianbin Zheng
Talanta 2017 Volume 165() pp:304-312
Publication Date(Web):1 April 2017
DOI:10.1016/j.talanta.2016.12.067
•An enhanced non-enzymatic electrochemical sensor of nitrite was designed by immobilizing high-quality palladium nanocubes decorated nitrogen-doped graphene (NGE/PdNC)nanocomposites on a GCE.•The wide linear range and high sensitivity for nitrite sensing were identified as 5.0×10-7 − 1.51×10-3 mol L-1 and 342.4 μA mM−1 cm−2, respectively.•The NGE/PdNC/GCE also showed a high reproducibility, stability and good selectivity.A nanocomposite of high-quality palladium nanocubes (PdNCs) decorated nitrogen-doped graphene (NGE/PdNC) was successfully prepared by using bromide ion as a capping agent and polyvinyl pyrrolidone as a stabilizer. The morphology and composition of NGE/PdNC nanocomposites were characterized by field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRD) and Raman spectra. To explore the application of NGE/PdNC nanocomposites in electrochemistry, the electrocatalytic response to nitrite at a NGE/PdNC-based electrode was investigated. Thus, a highly sensitive and selective electrochemical sensor for the detection of nitrite was constructed based on a glassy carbon electrode modified with the NGE/PdNC nanocomposites. The electrochemical behavior of this nanocomposites was studied by electrochemical impedance spectroscopy, cyclic voltammetry and chronoamperometry. The electrochemical investigations proved that the NGE/PdNC nanocomposites exhibited good electrocatalytic performance for the oxidation of nitrite, including a wide linear range from 5.0×10−7 to 1.51×10−3 mol L−1, a high sensitivity of 342.4 μA mM−1 cm−2 and a low detection limit of 0.11 μmol L−1 at the signal-to-noise ratio of 3 (S/N=3). This non-enzymatic sensor also showed a good reproducibility and stability. The obtained NGE/PdNC nanocomposites may be a potential composite for applying in the field of other electrochemical sensing, catalysis and optics.High-quality palladium nanocubes (PdNCs) decorated nitrogen-doped graphene (NGE/PdNC) nanocomposites was successfully prepared by using KBr as a capping agent and polyvinyl pyrrolidone as a stabilizer. Further, an enhanced electrochemical sensor for the detection of nitrite was constructed based on a GCE modified with the NGE/PdNC nanocomposites.
Co-reporter:Wushuang Bai, Qinglin Sheng, and Jianbin Zheng
ACS Sustainable Chemistry & Engineering 2016 Volume 4(Issue 9) pp:4895
Publication Date(Web):July 26, 2016
DOI:10.1021/acssuschemeng.6b01210
In this paper, platinum (Pt) nanomaterials with controlled morphologies are grown on the surface of flowerlike manganese dioxide (MnO2) respectively based on gas–liquid reaction. Then flowerlike three-dimensional (3D) nanostructures are formed, with successful synthesis of corresponding Pt/MnO2 nanocomposites. The obtained nanocomposites are characterized by scanning electron microscopy, energy-dispersive X-ray spectrum, transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. In addition, an interesting color-change phenomenon appeared with the Pt nucleation and growth progress which may be due to variation of the Mn valence state triggered by the reduction of Pt. This phenomenon can be used for naked-eye observation of materials’ growth states which is beneficial for investigation of synthetic mechanisms. At last, the Pt/MnO2 3D nanostructure exhibits perfect electrocatalytic properties toward oxidation of methanol. The four kinds of Pt/MnO2 composites are all used for electrochemical catalytic sensing of methanol respectively which indicates that the morphology of nanomaterials determines the catalytic properties. This research provides a new platform for controllable synthesis of nanomaterials and investigation of electrocatalysis based on morphology controlled nanomaterials.Keywords: 3D nanostructure; Electrocatalysis; Gas−liquid reaction; Manganese dioxide; Platinum nanoparticle
Co-reporter:Hongfang Zhang, Danlei Ning, Lina Ma, Jianbin Zheng
Analytica Chimica Acta 2016 Volume 902() pp:82-88
Publication Date(Web):1 January 2016
DOI:10.1016/j.aca.2015.10.028
•An ultrasensitive nonenzymatic electrochemical immunosensor for HIgG detection was developed.•AuNRs were used to catalyze the deposition of silver.•Detection signal was greatly amplified by self-assembly of AuNRs and the subsequent silver enhancement.•This immunosensor exhibited a extremely low detection limit.A novel electrochemical immunoassay was developed based on the signal amplification strategy of silver deposition directed by gold nanorods (AuNRs), which was in-situ assembled on the sandwich immunocomplex. The superstructure formed by the self-assembly of AuNRs provided abundant active sites for the nucleation of silver nanoparticles. In this pathway, the stripping current of silver was greatly enhanced. Using human immunoglobulin G (HIgG) as a model analyte, the ultrasensitive immunoassay showed a wide linear range of six orders of magnitude from 0.1 fg mL−1 to 100 pg mL−1, with the low detection limit down to 0.08 fg mL−1. The practicality of this electrochemical immunoassay for detection of HIgG in serum was validated with the average recovery of 93.9%. In addition, this enzyme-free immunoassay also has the advantages of acceptable reproducibility and specificity, and thus this immunosensing protocol can be extended to the detection of other low-abundant protein biomarkers.
Co-reporter:Ziyin Yang, Xiaohui Zheng, Zhi Li and Jianbin Zheng
Analyst 2016 vol. 141(Issue 15) pp:4757-4765
Publication Date(Web):31 May 2016
DOI:10.1039/C6AN00640J
In this study, we described the facile synthesis of carbon nitride dots–reduced graphene oxide nanocomposites (CNDs–rGO) and their application for the enhanced electrochemical determination of dopamine (DA) and uric acid (UA). CNDs–rGO were synthesized for the first time through a green and facile one-step approach, carried out by hydrothermal heat-treatment of an aqueous solution containing GO and chitosan without introduction of other reducing agents or surface modifier. Then, the morphology and composition of CNDs–rGO nanocomposites were characterized by transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. TEM observations revealed that CNDs with a size of about 5.0 nm were homogeneously and densely distributed on the surface of rGO. Electrochemical investigations indicated that CNDs–rGO nanocomposites exhibited an excellent performance toward DA and UA. The linear range for DA was estimated to be from 80 nM to 227 μM with a sensitivity of 154.3 μA mM−1 cm−2 and a low detection limit of 0.03 μM. Meanwhile, the linear range for UA was estimated to be from 80 nM to 328 μM with a high sensitivity of 178.1 μA mM−1 cm−2 and a low detection limit of 0.05 μM. Therefore, CNDs–rGO nanocomposites showed great application potential for constructing electrochemical sensors for the detection of DA and UA.
Co-reporter:Wushuang Bai, Qinglin Sheng and Jianbin Zheng
Analyst 2016 vol. 141(Issue 14) pp:4349-4358
Publication Date(Web):09 May 2016
DOI:10.1039/C6AN00632A
In this paper, we report a novel morphology-controlled synthetic method. Platinum (Pt) nanoparticles with three kinds of morphology (aggregation-like, cube-like and globular) were grown on the surface of graphene oxide (GO) using a simple gas–liquid interfacial reaction and Pt/GO nanocomposites were obtained successfully. According to the experimental results, the morphology of the Pt nanoparticles can be controlled by adjusting the reaction temperature with the protection of chitosan. The obtained Pt/GO nanocomposites were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR). Then the Pt/GO nanocomposites with the three kinds of morphology were all used to fabricate electrochemical sensors. The electrochemical experimental results indicated that compared with various reported electrochemical sensors, the Pt/GO modified sensors in this work exhibit a low detection limit, high sensitivity and an extra wide linear range for the detection of nitrite. In addition, the synthesis of Pt particles based on a gas–liquid interfacial reaction provides a new platform for the controllable synthesis of nanomaterials.
Co-reporter:Qinglin Sheng, Duo Liu and Jianbin Zheng
New Journal of Chemistry 2016 vol. 40(Issue 8) pp:6658-6665
Publication Date(Web):20 May 2016
DOI:10.1039/C6NJ01264G
NiCo alloy nanoparticles anchored on polypyrrole/reduced graphene oxide nanocomposites (NiCo/PPy/RGO) were successfully constructed through in situ chemical polymerization and a coreduction process for glucose sensing. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were employed to characterize the morphology and composition of NiCo/PPy/RGO. The electrochemical properties of the sensor were investigated by cyclic voltammetry and amperometry. The results indicated that the supporting substrate of PPy/RGO nanocomposites can provide a larger surface area for the dispersion of NiCo nanoparticles. Meanwhile, this nonenzymatic glucose sensor displayed an excellent electrocatalytic activity to glucose oxidation, with a low detection limit of 0.17 μM (S/N = 3), a linear range of 0.5 μM–4.1 mM, and a sensitivity of 153.5 μA mM−1 cm−2. The present study demonstrates that the NiCo/PPy/RGO composites are promising electroactive materials for developing non-enzymatic glucose sensors.
Co-reporter:Zhi Li, Xiaohui Zheng and Jianbin Zheng
New Journal of Chemistry 2016 vol. 40(Issue 3) pp:2115-2120
Publication Date(Web):16 Dec 2015
DOI:10.1039/C5NJ02582F
Au@Ag nanoparticles (NPs) with good stability were prepared by a seed-mediated growth procedure in an aqueous solution of cetyltrimethylammonium chloride (CTAC) using spherical Au NPs as seeds. The as-prepared Au@Ag NPs were characterized by UV-visible spectroscopy and transmission electron microscopy (TEM), and further a nonenzymatic sensor was fabricated. The sensor exhibited excellent electrochemical performance towards H2O2 reduction at −0.2 V with a linear range from 5.0 μM to 10.0 mM, a limit of detection of 1.3 μM and a high sensitivity of 116.7 μA mM−1 cm−2 in N2-saturated phosphate buffer solution (PBS, pH 7.2). The results demonstrated that Au@Ag NPs promise to be a new platform for constructing H2O2 biosensors.
Co-reporter:Sai Zhang, Boqiang Li, Qinglin Sheng, Jianbin Zheng
Journal of Electroanalytical Chemistry 2016 Volume 769() pp:118-123
Publication Date(Web):15 May 2016
DOI:10.1016/j.jelechem.2016.03.025
•CuS–MWCNT nanocomposites were synthesized by employing MWCNTs as the catalyst support.•It was the first demonstration of fabricating the nitrite sensor based on CuS–MWCNT nanocomposites.•This sensor exhibits remarkable catalytic performance for nitrite detection.A functional nanocomposite of copper sulfide nanoparticles (CuS) supported on multiwall carbon nanotubes (MWCNTs) was synthesized and used for fabricating a nitrite sensor. X-ray diffraction analysis indicated that the product was CuS–MWCNTs. The morphology of the nanocomposite was studied by transmission electron microscopy. The glass carbon electrode modified with CuS–MWCNTs showed excellent electrocatalytic activities to the oxidation of nitrite in pH 7.0 phosphate buffer. The sensor could detect nitrite in a linear range of 1.0 μM to 8.1 mM with a correlation coefficient of 0.9989 and sensitivity of 131.2 μA mM− 1 cm− 2, a detection limit of 0.33 μM at a signal-to-noise ratio of 3. Additionally, the sensor exhibited good reproducibility, long-term stability, and anti-interference.
Co-reporter:Qian Wu, Qinglin Sheng, Jianbin Zheng
Journal of Electroanalytical Chemistry 2016 Volume 762() pp:51-58
Publication Date(Web):1 February 2016
DOI:10.1016/j.jelechem.2015.12.030
An efficient and rapid method was developed for the preparation of halloysite nanotubes (HNTs) loaded with Pd nanoparticles (PdNPs) to make a non-enzymatic sensor for glucose. In the preparation step, HNTs self-assembled by sodium dodecylsulfate (SDS) provide an ideal template for loading and arrangement of PdNPs on HNTs. The obtained PdNPs-HNTs nanocomposite material was placed on a glassy carbon electrode to detect glucose. The morphology and composition of the PdNPs-HNTs was investigated by using X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and energy-dispersive X-ray spectrum (EDX). Electrochemical impedance spectroscopy (EIS) reveals charge transfer resistance for the modified electrode. Cyclic voltammetry and amperometry were used to measure the electrocatalytic activity of the PdNP-HNT-modified electrode for non-enzymatic oxidation of glucose. The current response of the PdNP-HNT-modified electrode towards glucose covers two linear regions (0.5 μM to 2.0 mM and 2.0 mM to 15.0 mM). The detection limit is 0.43 μM. The present study indicated that the combination of PdNPs and HNTs endows the sensor with excellent electrocatalytic activity, selectivity, good storage stability and sensitivity.
Co-reporter:Ning Zhang, Qinglin Sheng, Yuanzhen Zhou, Sheying Dong, Jianbin Zheng
Journal of Electroanalytical Chemistry 2016 Volume 781() pp:315-321
Publication Date(Web):15 November 2016
DOI:10.1016/j.jelechem.2016.07.012
•FeOOH@PDA-Ag electrocatalyst was achieved via in situ reduction at room temperature.•The obtained FeOOH@PDA-Ag nanocomposites were used for fabricating a novel non-enzymatic H2O2 sensor.•This sensor had excellent electrocatalytic property toward the reduction of H2O2.A well-dispersed Ag nanoparticle (Ag NP) anchored on rod-like Ferric oxyhydroxide@polydopamine (FeOOH@PDA) electrocatalyst was achieved via in situ reduction at room temperature. The obtained FeOOH@PDA-Ag nanocomposites were used for fabricating a novel non-enzymatic H2O2 sensor. The relationship between the sensing interface material and the sensor performance was studied, and a new method for the detection of H2O2 was established. The composition and morphology of the nanocomposites were characterized by transmission electron microscopic (TEM), X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS), which indicated that large numbers of Ag NPs with a narrow size were uniformly distributed on the surface of FeOOH@PDA. The electrochemical investigation showed that the nanocomposites had excellent electrocatalytic property toward the reduction of H2O2, and the sensor displayed a linear response to H2O2 in the range of 7.5 μM–18.8 mM with a detection limit of 2.5 μM at a signal-to-noise ratio of 3 and a sensitivity of 11.8 μA mM− 1 cm− 2. Compared with other non-enzymatic H2O2 sensors, the linear range of this sensor improved one order of magnitude. Moreover, the good analytical performance, low cost and facile preparation method made this novel material a promising candidate for the development of effective non-enzymatic H2O2 sensor.
Co-reporter:Ziyin Yang, Xiaohui Zheng, and Jianbin Zheng
Industrial & Engineering Chemistry Research 2016 Volume 55(Issue 46) pp:12161-12166
Publication Date(Web):October 31, 2016
DOI:10.1021/acs.iecr.6b02953
A novel strategy is developed to synthesize prussian blue nanocubes/hollow polypyrrole (PB/H-PPy) nanocomposites for enhanced electrochemical determination of hydrogen peroxide (H2O2). PB/H-PPy nanocomposites were prepared through a facile approach, where Fe3O4 spheres acted as both the template and source of Fe3+. It was found that the dissolving of Fe3O4 in an acidic environment not only led to the successful formation of a hollow structure of PPy but also provided Fe3+ and assisted the formation of PB around H-PPy, therefore leading to the formation of PB/H-PPy. The morphology, structure, and electrochemical properties of PB/H-PPy were characterized by transmission electron microscopy, field-emitting scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and electrochemical techniques. The results indicated that a large number of PB nanocubes were densely distributed on the surface of H-PPy. Meanwhile, the combination of PB with H-PPy made the sensor based on PB/H-PPy exhibit an excellent performance toward H2O2 detection with a wide linear range of 5.0 μM to 2.775 mM, a high sensitivity of 484.4 μA mM–1 cm–2, and a low detection limit of 1.6 μM (S/N = 3). This work provided a new approach for the rational design and fabrication of an electrocatalytic material with improved catalytic activity.
Co-reporter:Ziyin Yang, Xiaohui Zheng and Jianbin Zheng
RSC Advances 2016 vol. 6(Issue 63) pp:58329-58335
Publication Date(Web):13 Jun 2016
DOI:10.1039/C6RA06366G
Ag nanoparticles/polyaniline/halloysite nanotube (AgNPs/PANI/HNTs) nanocomposites were synthesized and used for fabricating nonenzymatic H2O2 sensor. AgNPs/PANI/HNTs nanocomposites were synthesized through the direct loading of preformed AgNPs over the surface of PANI/HNTs. The morphology and composition of the nanocomposites were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), energy-dispersive X-ray spectrum (EDX) and X-ray diffraction spectrum (XRD). SEM and TEM observations reveal that large numbers of AgNPs were distributed on the surface of PANI/HNTs. The electrochemical investigations indicate that the sensor based on AgNPs/PANI/HNT exhibited an excellent performance toward H2O2 with a wide linear range of 0.5 μM to 4.7 mM, a high sensitivity of 74.8 μA mM−1 cm−2 and a low detection limit of 0.3 μM (S/N = 3).
Co-reporter:Zhi Li, Xiaohui Zheng, Qinglin Sheng, Ziyin Yang and Jianbin Zheng
RSC Advances 2016 vol. 6(Issue 14) pp:11218-11225
Publication Date(Web):21 Jan 2016
DOI:10.1039/C5RA26857E
Au@Ag nanoparticles (NPs) were prepared by a seed-mediated growth procedure using spherical Au NPs as seeds at a gas/liquid interface and further used to fabricate a nonenzymatic hydrogen peroxide (H2O2) sensor. The as-prepared Au@Ag NPs were characterized by UV-visible spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS). TEM and DLS analysis indicates that the obtained Au@Ag NPs are highly dispersed and possess narrow size distributions. The electrochemical behavior of the nonenzymatic sensor suggests that the Au@Ag NPs modified glassy carbon electrode exhibited a high sensitivity of 251.9 μA mM−1 cm−2 for electrochemical detection of H2O2 at a potential as low as −0.1 V. The results demonstrate that Au@Ag NPs should be promising materials for an electrochemical sensor in practical applications.
Co-reporter:Ziyin Yang, Xiaohui Zheng, Jianbin Zheng
Synthetic Metals 2016 Volume 221() pp:153-158
Publication Date(Web):November 2016
DOI:10.1016/j.synthmet.2016.08.020
•Prussian blue/polyaniline/graphene oxide (PB/PANI/GO) nanocomposites were synthesized through a facile one-step approach.•In the process, aniline acted as both the precursor of PANI and the reductant for FeCl3–K3[Fe(CN)6], making polymerization of aniline and anchoring of PB nanoparticles on PANI/GO occur simultaneously.•PB/PANI/GO nanocomposites were employed to fabricate H2O2 sensor.•This sensor exhibited remarkable catalytic performance for H2O2 detection.Prussian blue/polyaniline/graphene oxide (PB/PANI/GO) nanocomposites were synthesized and used for electrochemical sensing of hydrogen peroxide (H2O2). PB/PANI/GO nanocomposites were synthesized through a facile one-step approach, where aniline acted as both the precursor of PANI and the reductant for FeCl3–K3[Fe(CN)6], therefore making polymerization of aniline and anchoring of PB nanoparticles on PANI/GO occur simultaneously. Then, the nanocomposites were characterized by transmission electron microscopy (TEM), X-ray diffraction spectroscopy (XRD), fourier transform infrared spectroscopy (FTIR) and electrochemical techniques. The results indicated that PB nanoparticles with the size of about 4.0 nm were homogeneously distributed on the surface of PANI/GO, which made the sensor based on PB/PANI/GO exhibit an excellent performance toward H2O2 detection with a wide linear range of 5.0 μM to 1.275 mM, a sensitivity of 60.16 μA mM−1 cm−2 and a low detection limit of 1.9 μM (S/N = 3).
Co-reporter:Dejiang Rao, Qinglin Sheng and Jianbin Zheng
Analytical Methods 2016 vol. 8(Issue 24) pp:4926-4933
Publication Date(Web):25 May 2016
DOI:10.1039/C6AY01316C
Herein, we report a simple and attractive self-assembly strategy for preparing graphene oxide–multiwalled carbon nanotube–(1-pyrenemethylamine)–gold (GO–MWCNT–PMA–Au) nanocomposites using 1-pyrenemethylamine (PMA) as a coupling agent. The morphology and composition of the nanocomposites were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). Further, a non-enzymatic nitrite sensor was fabricated by immobilizing GO–MWCNT–PMA–Au nanocomposites on a glassy carbon electrode (GCE). To obtain the optimal electrochemical experimental conditions, the effects of pH value and the volume of the as-prepared Au nanoparticle suspension were carefully investigated. Its electrochemical sensing properties were studied by cyclic voltammetry and differential pulse voltammetry. The electrochemical investigation showed that the GO–MWCNT–PMA–Au nanocomposites exhibited good catalytic performance for the oxidation of nitrite. The nitrite electrochemical sensor presented a wide linear range from 2.0 × 10−6 to 1.0 × 10−2 mol L−1, a high sensitivity of 483.51 μA mM−1 cm−2 and a low detection limit of 0.67 μmol L−1 at a signal-to-noise ratio of 3 (S/N = 3). It also exhibited good anti-interference capability and stability. This paper provides a self-assembly strategy for preparing nanocomposites which are used to construct improved electrochemical sensors.
Co-reporter:Ziyin Yang, Xiaoqin Yan, Zhi Li, Xiaohui Zheng and Jianbin Zheng
Analytical Methods 2016 vol. 8(Issue 7) pp:1527-1531
Publication Date(Web):19 Jan 2016
DOI:10.1039/C5AY03258J
Cu2O/AlOOH/rGO nanocomposites were synthesized by employing AlOOH/rGO as the support for Cu2O catalysts and then the nanocomposites were used for fabricating nonenzymatic glucose sensors. The morphology and composition of the nanocomposites were characterized by transmission electron microscopy and X-ray diffraction spectroscopy. Electrochemical investigations indicate that the nanocomposites possess an excellent performance toward glucose with a wide linear range of 5.0 μM to 14.77 mM, a sensitivity of 155.1 μA mM−1 cm−2 and a low detection limit of 2.6 μM. These results indicated that the Cu2O/AlOOH/rGO modified electrode can act as a promising non-enzymatic sensor for glucose detection.
Co-reporter:Jiangtao Liu, Mingying Zhang, Jianbo Liu and Jianbin Zheng
Analytical Methods 2016 vol. 8(Issue 5) pp:1084-1090
Publication Date(Web):02 Dec 2015
DOI:10.1039/C5AY02672E
An Ag–graphene nanocomposite was firstly prepared using a one-step thermal reduction, then an Ag@Pt core–shell nanostructure was obtained via a galvanic replacement reaction. The Ag@Pt–graphene nanocomposite was successfully synthesized and further fabricated into an electrochemical sensor of H2O2. Its electrochemistry and electrocatalytic behavior towards H2O2 were investigated. The results exhibited that this sensor had excellent electrocatalytic properties towards H2O2. The reduction peak current signals had a good linear dependence on H2O2 concentration in the range from 5.0 μmol L−1 to 12.4 mmol L−1, and the detection limit was 0.9 μmol L−1 (S/N = 3). The preparation method is environmentally friendly and can make Ag, Pt and graphene nanomaterials become a unified whole, introducing a synergistic effect between the nanoparticles effectively, leading to a superior electrocatalytic ability compared to GO or the Ag–graphene nanocomposite. The results indicate that the Ag@Pt–graphene nanocomposite has great application potential for use in electrochemical sensors.
Co-reporter:Qinglin Sheng;Ruixiao Liu;Hongfang Zhang
Journal of the Iranian Chemical Society 2016 Volume 13( Issue 7) pp:1189-1195
Publication Date(Web):2016 July
DOI:10.1007/s13738-016-0833-y
An electrochemical l-tryptophan sensor based on tellurium nanorods modified glassy carbon electrode was proposed. The tellurium nanorods were synthesized by a chemical reduction method. The morphology and structures of the nanorods were characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). Owing to the special structure of the tellurium nanorods, the sensor exhibits excellent electrocatalytic ability towards the oxidation of l-tryptophan and shows linearity in the range from 0.02 to 11.48 μM with a sensitivity of 256 μA mM−1 cm−2 with a correlation coefficient of 0.9945. The detection limit was 0.01 μM with signal-to-noise ratio of 3, and the response time was found to be 2 s. Moreover, the sensor also exhibited long-term stability, good reproducibility and anti-interference, thus holding promise for sensing of l-tryptophan in practice.
Co-reporter:Dejiang Rao, Qinglin Sheng, Jianbin Zheng
Sensors and Actuators B: Chemical 2016 Volume 236() pp:192-200
Publication Date(Web):29 November 2016
DOI:10.1016/j.snb.2016.05.160
•Novel graphene oxide/chitosan/platinum nanocomposite was successfully synthesized by using chitosan as protective agent and dispersant.•Chitosan was used to disperse platinum nanoparticles, and then the aggregation of platinum nanoparticles was avoided.•A hydrazine electrochemical sensor were constructed via immobilizing graphene oxide/chitosan/platinum nanocomposites on a glassy carbon electrode.•Compared with the previous reports, this hydrazine sensor showed a low catalytic potential and high sensitivity.In this paper, a novel graphene oxide/chitosan/platinum (GO/CTS/Pt) nanocomposite was successfully synthesized by using CTS as protective agent and dispersant. Further, a hydrazine electrochemical sensor was constructed by immobilizing GO/CTS/Pt nanocomposites on a glassy carbon electrode (GCE). The morphology and composition of the nanocomposites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The electrochemical investigations indicated that the GO/CTS/Pt modified GCE showed excellent electrocatalytic ability towards the oxidation of hydrazine. The current responses of the GO/CTS/Pt modified GCE towards the addition of hydrazine showed a wide linear range from 2.0 × 10−5 to 1.0 × 10−2 mol L−1 at a low applied potential of 0 V (versus SCE), and the low detection limit was 3.6 μmol L−1 at the signal-to-noise ratio of 3. Moreover, the sensor also exhibited good reproducibility, stability and selectivity for hydrazine sensing. This study suggests that the GO/CTS/Pt nanocomposites might be further applied to other fields with great potential.
Co-reporter:Yan Wang, Sai Zhang, Wushuang Bai, Jianbin Zheng
Talanta 2016 Volume 149() pp:211-216
Publication Date(Web):1 March 2016
DOI:10.1016/j.talanta.2015.11.040
•Three-dimension (3D) morphology of Cu-MnO2-MWCNTs nanocomposites is very novel.•Copper nanoparticles have a fairly narrow nanoparticle size distribution.•The copper nanoparticles were applied to fabricate a non-enzymatic glucose sensor.•This sensor exhibits remarkable catalytic performance for glucose detection.A nonenzymatic glucose sensor based on Cu/MnO2/MWCNTs nanocomposite modified glass carbon electrode was fabricated by an electrochemical method. Transmission electron microscopic (TEM) measurement showed that MnO2 in the nanocomposite held a nanostructure of three-dimension (3D) spheres assembled by many densely arranged nanosheets. The electrocatalytic activity of the present sensor toward the oxidation of glucose was investigated by amperometry. The current response was linearly related to glucose concentration in a range from 6.4×10−7–2.0×10−3 mol L−1 with a sensitivity of 494 μA mM−1 cm−2 and a correlation coefficient of 0.9990, and another range from 10 to 1000 μM with a sensitivity of 1302 μA mM−1 cm−2 and a correlation coefficient of 0.9990. The detection limit was estimated to be 0.17 μM at a signal-to-noise ratio of 3, and the response time was found to be 3 s.The Cu/MnO2/MWCNTs nanocomposites accelerate the electron transfer and successfully realized glucose catalytic oxidation.
Co-reporter:Wushuang Bai, Qinglin Sheng, Jianbin Zheng
Talanta 2016 Volume 150() pp:302-309
Publication Date(Web):1 April 2016
DOI:10.1016/j.talanta.2015.12.030
•Electrosensing of nitrite is performed under control of hydrophobic force.•Zero-current method is used to study electrochemical behavior of electrode.•GO/POSS modified sensor exhibits perfect performance.In this paper, we report a novel hydrophobic interface controlled electrochemical sensing of nitrite based on polyhedral oligomeric silsesquioxane/ reduced graphene oxide nanocomposite (POSS/rGO). The POSS/rGO is prepared by one step hydrothermal synthesis method, and characterized by transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FT-IR), Zeta-potential measurement analyzer, electrochemical impedance spectroscopy (EIS) and zero current potential method respectively. Then the POSS/rGO composite is used to fabricate electrochemical sensor for nitrite detection. According to experimental results, it is found that under control of hydrophobic force, the current peak will be shifted to lower potential (0.72 V) and the possible reason has been analyzed in manuscript. In addition, the POSS/rGO based sensor also has wide linear range (0.5 μM to 120 mM), low detection limit (0.08 μM) and good selectivity. In a word, the hydrophobic force controlled detection in this paper will provide a new platform for electrochemical sensing.The hydrophobic interface will be formed when GO/POSS modified electrode is immersed in nitrite solution, and the thickness of double layer between modified electrode and nitrite solution will be changed which makes the electrochemical oxidation of nitrite easier.
Co-reporter:Qian Wu;Qinglin Sheng;Jianbin Zheng
Microchimica Acta 2016 Volume 183( Issue 6) pp:1943-1951
Publication Date(Web):2016 June
DOI:10.1007/s00604-016-1829-0
A sandwich structured nanocomposite consisting of mildly reduced graphene oxide modified with silver nanoparticles supported on Co3O4 was synthesized and used for fabricating a nonenzymatic sensor for H2O2. The morphology and composition of the nanocomposite was characterized by transmission electron microscopy, scanning electron microscopy, X-ray powder diffraction and FTIR. The composite was placed on a glassy carbon electrode which then displayed excellent performance in terms of electroreduction of H2O2. The H2O2 sensor, if operated at pH 7.4 at a working potential of 0.4 V (vs. SCE) has the following features: (a) linearity in the 0.1 μM to 7.5 mM concentration range; (b) a sensitivity of 146.5 μA∙mM‾1∙cm‾2; (c) a 35 nM detection limit at a signal-to-noise ratio of 3, and (d) a response time of 2 s. The sensor is long-term stable, well reproducible and selective.
Co-reporter:Dejiang Rao;Jian Zhang;Jianbin Zheng
Journal of the Iranian Chemical Society 2016 Volume 13( Issue 12) pp:2257-2266
Publication Date(Web):2016 December
DOI:10.1007/s13738-016-0944-5
The high-quality CTAB-stabilized gold nanorods (Au NRs) were prepared by the way of seed-mediated protocol. The microstructure and composition of the Au NRs were identified by transmission electron microscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and UV–visible spectroscopy. Further, a novel non-enzymatic electrochemical sensor of nitrite based on Au NRs–Nafion-modified glassy carbon electrode (GCE) was successfully developed. Under the optimum experimental conditions, the electrochemical behaviors of nitrite on the Au NRs–Nafion-modified GCE were systematically studied by electrochemical impedance spectroscopy, cyclic voltammetry and chronoamperometry. The electrochemical investigations indicated that the Au NRs–Nafion-modified GCE had a wide linear range of 3.0 × 10−6–6.0 × 10−3 mol L−1, an acceptable sensitivity of 130.9 ± 0.05 μA mM−1 cm−2, a fast response time of 3 s and a low detection limit of 0.64 ± 0.02 μmol L−1 at the signal-to-noise ratio of 3 (S/N = 3). Additionally, the electrochemical sensor also showed good stability and favorable anti-interference capability for the detection of nitrite.
Co-reporter:Sai Zhang, Jianbin Zheng
Talanta 2016 Volume 159() pp:231-237
Publication Date(Web):1 October 2016
DOI:10.1016/j.talanta.2016.06.014
•The crystal MnO2 nanotubes loaded on Ag@C core–shell matrices and their nanocomposites were used for fabricating a non-enzymatic hydrogen peroxide sensor.•The experimental results reveal that the obtained Ag@C are globular and of uniform size, providing more binding sites for the adhesion of MnO2 nanotubes.•Besides, the electron transfer rate between the electrode and the electrolyte also greatly increased, thus further improve the MnO2 catalytic perfoamance towards H2O2.•As a result, the novel sensor exhibits good electrocatalytic activities toward H2O2.A nonenzymatic hydrogen peroxide sensor was fabricated by combing the crystal α-MnO2 nanotubes and Ag@C core–shell matrix with their own superior characteristics. The morphology, size and electrochemical of the sensing interface materials and the relationship between the electrical catalytic properties and sensor response performance were also studied, established a new method for the detection of hydrogen peroxide (H2O2). The structure and morphology of hollow tubular-like MnO2 and MnO2-Ag@C film were characterized by scanning electron micrograph (SEM), transmission electron microscopy (TEM) and X-ray diffraction. The electrochemical properties of the sensor were explored by cyclic voltammetry and amperometry. The investigation showed that the MnO2-Ag@C at the sensor exhibited a high electrocatalytic activity towards electroreduction of hydrogen peroxide; and under the optimal conditions, the linear ranges of hydrogen peroxide were 0.5 μM to 5.7 mM with a low detection limit of 0.17 μM (S/N=3) and high sensitivity of 127.2 μA mM−1 cm−2. Compared with other nonenzymatic hydrogen peroxide sensor, the fabricated sensor own lower detection limit, demonstrating that MnO2-Ag@C nanocomposite film will be a new promising platform for the construction of hydrogen peroxide sensors.The MnO2-Ag@C nanocomposites accelerate the electron transfer and successfully realized hydrogen peroxide catalytic reduction.
Co-reporter:DEJIANG RAO;QINGLIN SHENG;JIANBIN ZHENG
Journal of Chemical Sciences 2016 Volume 128( Issue 9) pp:1367-1375
Publication Date(Web):2016 September
DOI:10.1007/s12039-016-1146-5
Novel nanocomposite of nickel hydroxide/chitosan/platinum was successfully synthesised with chitosan (CS) as a dispersing and protecting agent. Its potential application in non-enzymatic electrochemical glucose sensor was studied. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) were used to characterize the composition and morphology of this nanocomposite. The electrochemical investigations of this glucose sensor exhibited remarkable analytical performances towards the oxidation of glucose. In particular, glucose can be selectively and sensitively detected in a wide linear range from 3.0 × 10−6 to 1.1 × 10−2 mol ⋅L−1 with a detection limit of 0.56 ±0.03 μmol⋅L−1 at a signal-tonoise ratio of 3 (S/N = 3). Furthermore, the Ni(OH)2/CS/Pt nanocomposite-modified GCE also showed an acceptable anti-interference ability and stability. Importantly, the Ni(OH)2/CS/Pt based sensor can be used to detect trace amount of glucose in serum samples. The results demonstrated that the Ni(OH)2/CS/Pt nanocomposite can be potentially useful to construct a new glucose sensing platform.
Co-reporter:Cheng-Cheng Qi;Jian-Bin Zheng
Chemical Papers 2016 Volume 70( Issue 4) pp:404-411
Publication Date(Web):2016 April
DOI:10.1515/chempap-2015-0224
To achieve highly sensitive nonenzymatic detection of H2O2, a novel electrochemical sensor based on Fe3O4-Ag nanocomposites was developed. Nanocomposites were synthesized by reducing [Ag(NH3)2]+ at the gas/liquid interface in the presence of silver seeds and confirmed by transmission electron microscopy and X-ray diffractometry. Electrochemical investigations indicate that the sensor is able to detect H2O2 within a wide linear range of 0.5 μM to 4.0 mM, sensitivity of 135.4 μA mM−1 cm−2 and low detection limit of 0.2 μM (S/N = 3). Additionally, the sensor exhibits good anti-interference ability, stability and repeatability. These results show that the Fe3O4-Ag nanocomposite is a promising electrocatalytic material for sensors construction.
Co-reporter:Qinglin Sheng;Yu Shen;Qian Wu;Jianbin Zheng
Journal of Solid State Electrochemistry 2016 Volume 20( Issue 12) pp:3315-3322
Publication Date(Web):2016 December
DOI:10.1007/s10008-016-3353-x
The direct electrochemistry and electrocatalysis of cytochrome c (Cyt c) based on dandelion-like bismuth sulfide (d-Bi2S3) nanoflowers have been developed. The morphologies and composition of the d-Bi2S3 were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS). Then, the electrochemical behaviors of Cyt c immobilized within the d-Bi2S3/chitosan film and its electrocatalytic ability toward hydrogen peroxide (H2O2) reduction were investigated by cyclic voltammetry. The electron transfer rate constant was estimated to be 13.1 s−1, suggesting that a fast direct electron transfer was realized. The prepared Cyt c/d-Bi2S3/chitosan nanobiocomposite-modified electrode possessed excellent electrocatalytic ability toward H2O2 reduction that showed linearity in the range from 0.5 μM to 1.56 mM with a correlation coefficient of 0.9993. The detection limit was 0.2 μM on signal-to-noise ratio of 3. In addition, the d-Bi2S3 nanoflowers may be also applied to direct electron transfer of other redox proteins.
Co-reporter:Dejiang Rao;Xinjin Zhang;Qinglin Sheng;Jianbin Zheng
Microchimica Acta 2016 Volume 183( Issue 9) pp:2597-2604
Publication Date(Web):2016 September
DOI:10.1007/s00604-016-1902-8
A composite material obtained by ultrasonication of graphene oxide (GO) and multi-walled carbon nanotubes (MWCNTs) was loaded with manganese dioxide (MnO2), poly(diallyldimethylammonium chloride) and gold nanoparticles (AuNPs), and the resulting multilayer hybrid films were deposited on a glassy carbon electrode (GCE). The microstructure, composition and electrochemical behavior of the composite and the modified GCE were characterized by transmission electron microscopy, Raman spectra, energy-dispersive X-ray spectroscopy, electrochemical impedance spectroscopy and cyclic voltammetry. The electrode induces efficient electrocatalytic oxidation of dopamine at a rather low working voltage of 0.22 V (vs. SCE) at neutral pH values. The response is linear in the 0.5 μM to 2.5 mM concentration range, the sensitivity is 233.4 μA·mM‾1·cm‾2, and the detection limit is 0.17 μM at an SNR of 3. The sensor is well reproducible and stable. It displays high selectivity over ascorbic acid, uric acid and glucose even if these are present in comparable concentrations.
Co-reporter:DEJIANG RAO;JIAN ZHANG;JIANBIN ZHENG
Journal of Chemical Sciences 2016 Volume 128( Issue 5) pp:839-847
Publication Date(Web):2016 May
DOI:10.1007/s12039-016-1062-8
Silver nanoparticles were prepared by chemical reduction of acetaldehyde gas in the absence of protective gas, and Ag/FePO4 nanocomposites were synthesised by modified silver mirror reaction at a gas-liquid interface. A hydrogen peroxide (H2O2) electrochemical sensor was constructed through immobilizing Ag/FePO4 nanocomposites on gold (Au) electrode. The morphology and composition of the nanocomposites were characterized by transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS). The electrochemical investigations of the sensor indicated that it exhibited excellent analytical performance with a wide linear range from 3.0×10−5 to 1.1×10−2 mol⋅L−1 and a low detection limit of 4.7 μmol⋅L−1 at a signal-to-noise ratio of 3. Meanwhile, it also showed acceptable reproducibility and anti-interference ability. This study may provide a new method for the synthesis of highly dispersed metal nanoparticles which might be used in other related fields.
Co-reporter:Wushuang Bai, Qinglin Sheng, Fei Nie, and Jianbin Zheng
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 51) pp:28377
Publication Date(Web):December 9, 2015
DOI:10.1021/acsami.5b09094
Controllable synthesis of manganese oxides was performed via a simple one-step synthetic method. Then obtained manganese oxides which exhibit flower-like, cloud-like, hexagon-like, and rod-like morphologies were modified by formaldehyde based on a simple self-made gas–liquid reaction device respectively and the modified manganese oxides with coral-like, scallop-like and rod-like morphology were synthesized accordingly. The obtained materials were characterized and the formation mechanism was also researched. Then the modified manganese oxides were used to fabricate electrochemical sensors to detect H2O2. Comparison of electrochemical properties between three kinds of modified manganese oxides was investigated and the best one has been successfully employed as H2O2 sensor which shows a low detection limit of 0.01 μM, high sensitivity of 162.69 μA mM–1 cm–2, and wide linear range of 0.05 μM–12.78 mM. The study provides a new method for controllable synthesis of metal oxides, and electrochemical application of formaldehyde modified manganese oxides will provides a new strategy for electrochemical sensing with high performance, low cost, and simple fabrication.Keywords: controllable synthesis; electrochemical sensing; hydrogen peroxide; liquid-gas reaction; manganese oxide
Co-reporter:Qinglin Sheng, Ni Cheng, Wushuang Bai and Jianbin Zheng
Chemical Communications 2015 vol. 51(Issue 11) pp:2114-2117
Publication Date(Web):03 Dec 2014
DOI:10.1039/C4CC08954E
An ultrasensitive cytosensor based on DNA-rolling-circle-amplification-directed enzyme-catalyzed polymerization is demonstrated. As a proof of concept, the cytosensor shows excellent sensitivity for MCF-7 cell detection with a lower detection limit of 12 cells per mL.
Co-reporter:Wushuang Bai, Qinglin Sheng, Xiaoyan Ma, and Jianbin Zheng
ACS Sustainable Chemistry & Engineering 2015 Volume 3(Issue 7) pp:1600
Publication Date(Web):May 25, 2015
DOI:10.1021/acssuschemeng.5b00297
It has been shown that the aggregation of particles is a big challenge in synthetics progress due to the Brownian movement and van der Waals potential among the particles. Thus, how to avoid aggregation to synthesize nanoparticles with homogeneous morphology has been greatly impressed by considerable researchers and many strategies have been implemented to solve the problem in recent years. In this paper, a novel method for silver nanoparticles (AgNPs) synthesize based on the regulation of hydrophobic interface was proposed, studies showed that in the presence of hydrophobic polyhedral oligomeric silsesquioxane (POSS), AgNPs with homogeneous morphology grown on interface between GO and silver nitrate (AgNO3) solution through a kind of common chemical reduction, and aggregation of AgNPs is avoided effectively without any protection under room temperature. The possible mechanism is discussed and the obtained AgNPs–POSS/rGO nanocomposites are used to fabricate electrochemical sensor for nitrobenzene, p-nitroaniline, and p-nitrobenzoic acid sensing. The composites have good ability to catalyze nitroaromatic compounds with the broad linear ranges of 0.5–155 ppm, 0.1–77 ppm, and 0.05–330 ppm and the low detection limits of 0.1, 0.05, and 0.02 ppm, respectively. The novel method provides a new platform for the synthesis of nanomaterials, the idea that changing hydrophobic/hydrophilic property of substrate material for growth of namomaterial may open up the traditional synthetic minds, and it will be expected to synthesize other optical, electronic, and magnetic nanomaterials.Keywords: Electrochemical catalysis; Graphene oxide; Interface regulation; Polyhedral oligomeric silsesquioxane; Silver nanoparticles;
Co-reporter:Chengcheng Qi, Jianbin Zheng
Journal of Electroanalytical Chemistry 2015 Volume 747() pp:53-58
Publication Date(Web):15 June 2015
DOI:10.1016/j.jelechem.2015.04.004
•Fe3O4/PPy/Ag nanocomposites with core/shell/shell structure were synthesized.•It was the first demonstration of fabricating the H2O2 sensor based on Fe3O4/PPy/Ag nanocomposites.•This sensor exhibits remarkable catalytic performance for hydrogen peroxide detection.Fe3O4/PPy/Ag nanocomposites with core/shell/shell structure were prepared and used for fabricating nonenzymatic H2O2 sensor. The nanocomposites were prepared with a three-step process, and proved by characterizations such as transmission electron microscopic, X-ray diffraction and X-ray photoelectron spectroscopy. The electrochemical investigation revealed that the composites had excellent catalytic property toward H2O2. The sensor could detect H2O2 with a wide linear range from 5 μM to 11.5 mM, and a low detection limit of 1.7 μM. Additionally, the sensor exhibited long-term stability, good reproducibility and anti-interference.
Co-reporter:Sai Zhang, Qinglin Sheng and Jianbin Zheng
RSC Advances 2015 vol. 5(Issue 34) pp:26878-26885
Publication Date(Web):10 Mar 2015
DOI:10.1039/C5RA01390A
Natural halloysite nanotubes (HNTs) were attached to the flower-like MnO2 and HNTs–MnO2 composites were obtained, then silver nanoparticles were successfully deposited on the surface of HNTs–MnO2 to produce Ag–HNTs–MnO2 nanocomposites and they were used for fabricating a non-enzymatic hydrogen peroxide (H2O2) sensor. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy and Fourier transform infrared spectroscopy were applied to investigate the structures and morphologies of the resultant samples. The Ag–HNTs–MnO2 composite-based modified electrode exhibited high eletrocatalytic activity to the reduction of H2O2 with a linear range of 2.0 μM to 4.71 mM, a detection limit of 0.7 μM (S/N = 3) and a sensitivity of 11.9 μA mM−1 cm−2. In addition, high specific surface area, low cost and good biocompatibility gives the modified electrode a bright perspective in biosensors and biocatalysis.
Co-reporter:Ziyin Yang, Chengcheng Qi, Xiaohui Zheng and Jianbin Zheng
New Journal of Chemistry 2015 vol. 39(Issue 12) pp:9358-9362
Publication Date(Web):23 Sep 2015
DOI:10.1039/C5NJ01621E
Silver nanoparticle-decorated graphene oxide (AgNPs–TWEEN–GO) was synthesized and used for fabricating a non-enzymatic H2O2 sensor. The nanocomposites were synthesized for the first time through a facile method using TWEEN 80 as the modifier for GO as well as the reducing and stabilizing agent for AgNPs. Transmission electron microscopy observations revealed that large numbers of AgNPs were distributed on the surface of the GO and the electrochemical investigations indicated that the nanocomposites possessed an excellent performance for the detection of H2O2. The linear range was estimated to be from 0.02 mM to 23.1 mM H2O2 with a low detection limit of 8.7 μM (S/N = 3) and a response time of 3 s.
Co-reporter:Hongfang Zhang, Danlei Ning and Jianbin Zheng
RSC Advances 2015 vol. 5(Issue 129) pp:106607-106612
Publication Date(Web):09 Dec 2015
DOI:10.1039/C5RA22654F
A novel human immunoglobulin G (HIgG) electrochemical immunosensor was developed based on nanosilver-doped bovine serum albumin microspheres (Ag@BSA). The immunosensor was prepared step-wise by first modifying the electrode with β-cyclodextrin functionalized gold nanoparticles followed by the immobilization of captured antibodies and then the formation of a sandwich-type immunocomplex to introduce Ag@BSA bionanoprobes on the sensor surface. The amplification pathway using the stripping voltammetric measurement of silver ions released from Ag@BSA to monitor the immunoreaction was first adopted. The immunosensor exhibited a large dynamic range of 1 fg mL−1 to 10 pg mL−1 and an ultralow detection limit of 0.5 fg mL−1 to HIgG. Moreover, the immunosensor also showed acceptable stability and reproducibility. This biosensor was applied to the detection of the HIgG level in real serum samples.
Co-reporter:Jian Zhang and Jianbin Zheng
Analytical Methods 2015 vol. 7(Issue 5) pp:1788-1793
Publication Date(Web):08 Jan 2015
DOI:10.1039/C4AY02881C
Ag/FeOOH nanocomposites were synthesized and then immobilized on a pencil graphite electrode (PGE), resulting in the development of a new enzyme-free hydrogen peroxide sensor. UV-Vis absorption spectroscopy and transmission electron microscopy (TEM) were used to characterize the composition and morphology of the nanocomposites. In an electrochemical investigation, the nanocomposites displayed excellent electrocatalytic performance for H2O2; the current response of the sensor was linear between H2O2 concentrations of 0.03 and 15.0 mM, with a detection limit of 22.8 μM at a signal-to-noise ratio of 3; the sensitivity of the sensor was 8.07 μA mM−1 cm−2 and the response time was 3 s. The sensor also displayed favourable anti-interference. This study may provide a good nanomaterial and a simple method for the development of hydrogen peroxide sensors.
Co-reporter:Sai Zhang, Bo-Qiang Li and Jian-Bin Zheng
Analytical Methods 2015 vol. 7(Issue 19) pp:8366-8372
Publication Date(Web):26 Aug 2015
DOI:10.1039/C5AY01710F
A new sandwich structure nanocomposite of Pt nanoparticles supported on PANI modified graphene was synthesized and used for fabricating a nitrite sensor. The morphology and composition of the nanocomposites were characterized using transmission electron microscopy and X-ray diffraction. Electrochemical investigations indicated that the nanocomposites possess an excellent electrochemical oxidation ability towards nitrites. The sensor exhibited two linear ranges: one from 0.4 μM to 0.99 mM with a correlation coefficient of 0.9974 and a sensitivity of 485.5 μA mM−1 cm−2; and another from 0.99 mM to 7.01 mM with a correlation coefficient of 0.9981 and a sensitivity of 154.3 μA mM−1 cm−2. The limit of detection (LOD) of this sensing system was 0.13 μM at a signal-to-noise ratio of 3. Additionally, the sensor exhibited good reproducibility, long-term stability, and anti-interference performance.
Co-reporter:Qinglin Sheng, Dan Zhang, Qian Wu, Jianbin Zheng and Hongsheng Tang
Analytical Methods 2015 vol. 7(Issue 16) pp:6896-6903
Publication Date(Web):17 Jul 2015
DOI:10.1039/C5AY01329A
A facile and effective electrochemical sensing technique was developed by the electrodeposition of Prussian blue on polyaniline (PANI) coated halloysite nanotubes (HNTs). Owing to the special structure of the PB-PANI-HNT nanocomposite, the sensor possessed excellent electrocatalytic ability towards H2O2 reduction. The amperometric study demonstrated that the H2O2 sensor exhibits good performance with a linearity in the range from 4 μM to 1064 μM. The limit of detection (LOD) was 0.226 μM (S/N = 3) and the sensitivity was calculated to be 0.98 μA (μM−1 cm−2). Moreover, the interference from the common interfering species such as glucose, ascorbic acid, dopamine and uric acid can be effectively avoided, and the sensors exhibit long-term stability, thus holding promise for the development of amperometric biosensors.
Co-reporter:Jianbo Liu, Jianbin Zheng, Juncai Zhang, Wushuang Bai and Jiangtao Liu
Analytical Methods 2015 vol. 7(Issue 12) pp:4979-4987
Publication Date(Web):30 Apr 2015
DOI:10.1039/C5AY00646E
The conformational changes of myoglobin (Mb) during urea-induced protein unfolding were investigated using an electrochemical method. Using several different concentrations of urea, Mb adsorbed onto a montmorillonite clay modified glassy carbon electrode (GCE) was denatured. It was determined from the relative differences in the percentage of Mb unfolding that urea-induced Mb unfolding is a one-step, two-state transition process. The results obtained using electrochemical analysis were in agreement with those obtained by UV-vis spectroscopy and fluorescence spectroscopy, confirming our observations. Thermodynamic parameters during the conformational changes were also calculated to further characterize the unfolding process of Mb. Furthermore, two typical denaturants, urea and acid, were synergistically utilized to maintain GCE incorporated Mb in its most unfolded state, while simultaneously maintaining the presence of heme groups. Under optimal conditions, the unfolded Mb/clay/GCE exhibited accelerated direct electron transfer relative to the native Mb/clay/GCE. Additionally, the sensitivity for the detection of H2O2 was increased nearly 10-fold, and the limit of detection (LOD) for H2O2 was reduced to 0.3 μM for the unfolded Mb/clay/GCE relative to the native Mb/clay/GCE. The present work introduces a simple and effective way to study the unfolding of metalloproteins and holds great promise for the design of novel sensitive biosensors.
Co-reporter:Yang Li;Jianbin Zheng;Qinglin Sheng;Bini Wang
Microchimica Acta 2015 Volume 182( Issue 1-2) pp:61-68
Publication Date(Web):2015 January
DOI:10.1007/s00604-014-1272-z
Inspired by water-soluble sacrificial template strategies, we have synthesized crystals of silver chloride (AgCl) consisting of a well-defined cubic exterior and a hollow interior. In a next step, silver nanoparticles (Ag-NPs) were attached to the hollow AgCl crystals via a photo-reduction process. The growth mechanism of the resulting Ag@AgCl nanoboxes is discussed, and their morphology and composition characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. The electrochemical investigation of the nanoboxes deposited on a glassy carbon electrode revealed its excellent property in terms of electrocatalytic reduction H2O2 at a potential as low as −0.1 V and with fast response (~1 s). The modified GCE responds to of H2O2 in the concentration range from 5.0 μM to 15.0 mM, the sensitivity is 88.8 μA mM−1 cm−2, and the detection limit is 1.7 μM at a signal-to-noise ratio of 3. The sensor also displays excellent selectivity and stability.
Co-reporter:Bo-Qiang Li;Fei Nie;Qing-Lin Sheng;Jian-Bin Zheng
Chemical Papers 2015 Volume 69( Issue 7) pp:911-920
Publication Date(Web):2015 July
DOI:10.1515/chempap-2015-0099
A functional Ag-Fe3O4-grapheme oxide magnetic nanocomposite was synthesized and used to prepare a nitrite sensor. Morphology and composition of the nanocomposites were characterized by a transmission electron microscope, UV-VIS spectroscopy, X-ray diffraction, and Fourier transform infrared spectra. Electrochemical investigation indicated that the nanocomposites possess excellent electrochemical oxidation ability towards nitrites. The sensor exhibited two linear ranges: one from 0.5 µM to 0.72 mM with a correlation coefficient of 0.996 and sensitivity of 1996 µA mM−1 cm−2; the other from 0.72 mM to 8.15 mM with a correlation coefficient of 0.998 and sensitivity of 426 µAmM−1 cm−2. The limit of detection of this sensing system was 0.17 µM at the signal-to-noise ratio of 3. Additionally, the sensor exhibited long-term stability, good reproducibility, and anti-interference.
Co-reporter:Mingying Zhang;Jiangtao Liu;Fei Nie
Journal of the Iranian Chemical Society 2015 Volume 12( Issue 9) pp:1535-1542
Publication Date(Web):2015 September
DOI:10.1007/s13738-015-0625-9
A new sandwich structure nanocomposite of Ag nanoparticles supported on TiO2-functionalized graphene nanosheet was synthesized, involving a simple chemical reduction of GO using TiCl3 as reducing agent and the in situ formation of TiO2 as linker between r-GO and Ag. Based on the Ag/TiO2/r-GO hybrid material, a novel electrochemical sensor for the determination of nitrite was constructed. The morphology and composition of the nanocomposite were characterized by transmission electron microscope and UV–vis absorption spectra. Electrochemical investigation indicated that Ag/TiO2/r-GO modified electrode exhibited excellent electrocatalytic performance for the oxidation of nitrite. The sensor showed a wide linear range from 1.0 µM to 1.1 mM, with the detection limit of 0.4 µM, the sensitivity of 112.0 μA mM−1 cm−2. Additionally, the proposed method was successfully applied to the detection of nitrite in water samples with obtained satisfactory results.
Co-reporter:Ziyin Yang, Chengcheng Qi, Xiaohui Zheng, Jianbin Zheng
Talanta 2015 Volume 140() pp:198-203
Publication Date(Web):1 August 2015
DOI:10.1016/j.talanta.2015.03.023
•AgNPs were synthesized at a gas/liquid interface in the presence of silver seeds.•AgNPs have a fairly narrow nanoparticle size distribution.•AgNPs were applied to fabricate a non-enzymatic sensor.•The sensor exhibits remarkable catalytic performance for H2O2 detection.Silver nanoparticles were synthesized by reducing [Ag(NH3)2]+ at a gas/liquid interface in the presence of silver seeds. Transmission electron microscopy (TEM) observations reveal that the size of these silver nanoparticles is around 35–40 nm with the average particle size of 37 nm. The silver nanoparticles were applied for the electrochemical sensor and electrochemical investigations indicate that the nanoparticles possess an excellent performance toward H2O2. The linear range is estimated to be from 5.0 μM to 4.0 mM with a low detection limit of 1.7 μM, a sensitivity of 166.7 μA mM−1 cm−2 and a response time of 3 s. Additionally, the sensor exhibits good anti-interference.
Co-reporter:Wushuang Bai, Fei Nie, Jianbin Zheng, and Qinglin Sheng
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 8) pp:5439
Publication Date(Web):March 24, 2014
DOI:10.1021/am500641d
A gas/liquid interface will be formed when the free volatilized methyl aldehyde gas begins to dissolve in to solution. On the basis of the traditional silver mirror reaction, silver nanoparticle–manganese oxyhydroxide–graphene oxide (Ag-MnOOH-GO) nanocomposite was synthesized at the gas/liquid interface without any protection of inert gas at room temprature. The morphology of the nanocomposites could be controlled by adjusting the reaction temperature and time. The morphology and composition of the nanocomposites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The composites were then applied for electrochemical sensing. The electrochemical investigation for the sensor indicates that it has excellent property to catalyze H2O2, and could detect H2O2 with a low detection limit of 0.2μM and wide linear range of 0.5 μM to 17.8 mM. The present study provides a general platform for the controlled synthesis of nanomaterials and can be extended to other optical, electronic, and magnetic nanocompounds.Keywords: graphene oxide; hydrogen peroxide sensor; MnOOH; silver mirror reaction; silver nanoparticles;
Co-reporter:Ni Cheng, Bing Du, Yuan Wang, Hui Gao, Wei Cao, Jianbin Zheng and Fan Feng
Food & Function 2014 vol. 5(Issue 5) pp:900-908
Publication Date(Web):28 Jan 2014
DOI:10.1039/C3FO60623F
The antioxidant potential of jujube honey, one of the most widely consumed honeys in China, has never been determined fully. In this study, jujube honey from six geographical origins in China was analyzed for individual phenolic acid, total phenolic content, and the antioxidant effect in chronic alcohol-related hepatic disease in mice. The results showed that jujube honey from Linxian of Shanxi province contained higher phenol levels, exhibited DPPH antioxidant activity, ferric ion reducing antioxidant power (FRAP) and protective effects against DNA damage. Treatment with jujube honey (Shanxi Linxian) for 12 weeks significantly inhibited serum lipoprotein oxidation, reduced the impact of alcoholism on aspartate aminotransferase (AST) and alanine aminotransferase (ALT). It also inhibited the generation of 8-hydroxy-2-deoxyguanosine (8-OHdG), lowered the levels of malondialdehyde (MDA) and increased the activity of hepatic glutathione peroxidase (GSH-Px). The study indicates that jujube honey exerts potent antioxidant activity and significant protection in hepatic disorders associated with chronic alcoholism. The protective effect is attributed to its antioxidant mechanisms and inhibition of oxidative degradation of lipids.
Co-reporter:Ruixiao Liu, Jianbin Zheng
Materials Letters 2014 Volume 125() pp:179-182
Publication Date(Web):15 June 2014
DOI:10.1016/j.matlet.2014.03.154
•The Chrysalidocarpus lutescens-like cobalt (Co) materials were prepared by electrodeposition without any template or surfactantand.•The possible formation process of the Co materials was reported.•The Co materials had excellent electrocatalytic activity for glucose oxidation.The chrysalidocarpus lutescens-like cobalt (Co) materials were prepared on an electrode of indium tin oxide (ITO) by electrodeposition strategy without any template or surfactant. The morphology and composition of the Co materials were characterized by transmission electron microscope, scanning electron microscope, energy-dispersive spectrum and X-ray diffraction. The electrochemical behavior and electrocatalytic performance of the Co materials were evaluated by cyclic voltammetry and chronoamperometry, and the results showed the Co materials had electrocatalytic activity for glucose oxidation. The catalytic current was linear with glucose concentration from 0.2 to 14 μM (n=25, R=0.9998) and from 15 to 225 μM (n=26, R=0.9967) with a detection limit of 0.06 μM at a signal-to-noise ratio of 3. All of these features made the Co materials a promising electrode material for non-enzymatic glucose sensor.
Co-reporter:Yan Dong, Qinglin Sheng, Jianbin Zheng and Hongsheng Tang
Analytical Methods 2014 vol. 6(Issue 21) pp:8598-8603
Publication Date(Web):29 Aug 2014
DOI:10.1039/C4AY01702A
In this work, a nonenzymatic reduced glutathione (GSH) sensor was constructed based on the electrodepoition of Ni–Al layered double hydroxides (Ni–Al LDHs) on multiwall carbon nanotubes (MWCNTs) modified glassy carbon electrode (GCE). The morphologies and compositions of Ni–Al LDHs/MWCNTs nanocomposite were investigated by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Cyclic voltammetry and amperometry were employed to explore the electrochemical properties and performance of Ni–Al LDHs/MWCNTs nanocomposites in sensing and detection. The results indicated that the response current of GSH oxidation at the Ni–Al LDHs/MWCNTs/GCE was obviously higher than that at the MWCNTs/GCE or the Ni–Al LDHs/GCE. The amperometric current of the sensor is proportional to the concentration of GSH in a linear range of 1.2 to 1630.0 μM with a detection limit of 0.7 μM at a signal-to-noise ratio of 3. In addition, the sensor exhibits easy preparation, low cost, good stability and anti-interference.
Co-reporter:Mingying Zhang, Qinglin Sheng, Fei Nie, Jianbin Zheng
Journal of Electroanalytical Chemistry 2014 730() pp: 10-15
Publication Date(Web):
DOI:10.1016/j.jelechem.2014.07.020
Co-reporter:Qinglin Sheng, Ruixiao Liu, Sai Zhang, Jianbin Zheng
Biosensors and Bioelectronics 2014 Volume 51() pp:191-194
Publication Date(Web):15 January 2014
DOI:10.1016/j.bios.2013.07.053
•A sensitive DNA nanostructure-based electrochemical biosensor for cocaine was established.•The sensor featured stable, sensitive, and regenerable functions.•Linear detection of cocaine ranged from 1.0 nM to 2.0 μM with LOD at 0.21 nM.•This strategy is applicable to other analytes with a suitable anti-target DNA, RNA aptamers or peptides.We proposed an ultrasensitive electrochemical cocaine biosensor based on the three-dimensional (3D) DNA structure conversion of nanostructure from Triangular Pyramid Frustum (TPFDNA) to Equilateral Triangle (ETDNA). The presence of cocaine triggered the aptamer-composed DNA nanostructure change from “Close” to “Open”, leading to obvious faradaic impedance changes. The unique properties with excellent stability and specific rigid structure of the 3D DNA nanostructure made the biosensing functions stable, sensitive, and regenerable. The Faradaic impedance responses were linearly related to cocaine concentration between 1.0 nM and 2.0 μM with a correlation coefficient of 0.993. The limit of detection was calculated to be 0.21 nM following IUPAC recommendations (3Sb/b). It is expected that the distinctive features of DNA nanostructure would make it potentially advantageous for a broad range of biosensing, bionanoelectronics, and therapeutic applications.
Co-reporter:Yan Dong, Jianbin Zheng
Journal of Molecular Liquids 2014 196() pp: 280-284
Publication Date(Web):
DOI:10.1016/j.molliq.2014.03.046
Co-reporter:Ruixiao Liu;Yang Han;Fei Nie;Rong Li
Journal of the Iranian Chemical Society 2014 Volume 11( Issue 6) pp:1569-1577
Publication Date(Web):2014 December
DOI:10.1007/s13738-014-0428-4
Nanofilms of titanium dioxide (TiO2) nanoparticles that mediate the assembly of polystyrene (PS) nanoparticles for immobilizing hemoglobin (Hb) on carbon ionic liquid electrode have been developed. Fourier transform infrared spectroscopy shows that Hb retains its native structure in TiO2–PS nanofilms. Scanning electron microscopy reveals that the nanofilms possess uniform morphology and Hb is immobilized on the surface of the nanofilms. Electrochemical investigation of the biosensor indicates that the direct electrochemistry of hemoglobin is realized on the nanofilms, and there is a formal potential of −0.320 V in deaerated buffer solutions; the biosensor shows good electrocatalytic activity toward the reduction of hydrogen peroxide with a linear range from 0.5 to 640 μM, a detection limit of 0.2 μM (S/N = 3) and a sensitivity of 103 μA mM−1. Thus, the nanofilms will have potential application in the design of novel electrochemical biosensors.
Co-reporter:Sai Zhang;Dawei Zhang;Qinglin Sheng
Journal of Solid State Electrochemistry 2014 Volume 18( Issue 8) pp:2193-2200
Publication Date(Web):2014 August
DOI:10.1007/s10008-014-2462-7
A novel polyaniline and titanium carbide (PANI–TiC) nanocomposite was synthesized by an in situ chemical oxidative polymerization method, and a hydrogen peroxide (H2O2) biosensor was fabricated by PANI–TiC with hemoglobin (Hb)-modified glassy carbon electrode (GCE). Scanning electron microscope and energy dispersive X-ray spectroscopy showed the morphology and ingredient of PANI–TiC. Electrochemical investigation of the biosensor showed a pair of well-defined, quasi-reversible redox peaks with Epa = −0.318 V and Epc = −0.356 V (vs SCE) in 0.1 M, pH 7.0 sodium phosphate-buffered saline at the scan rate of 150 mV s−1. Transfer rate constant (ks) was 2.01 s−1. The Hb/PANI–TiC/GCE showed a good electrochemical catalytic response for the reduction of H2O2 with the linear range from 0.5 to 285.5 μM and the detection limit of 0.2 μM (S/N = 3). The apparent Michaelis–Menten constant (Km) was estimated to be 1.21 μM. Therefore, the PANI–TiC as a novel matrix opened up a further possibility for study on the design of enzymatic biosensors with potential applications.
Co-reporter:Qing-Lin Sheng, Rui-Xiao Liu, Jian-Bin Zheng and Jun-Jie Zhu
Nanoscale 2013 vol. 5(Issue 16) pp:7505-7511
Publication Date(Web):30 May 2013
DOI:10.1039/C3NR01576A
A novel and versatile biosensing platform based on the structural conversion of 3D DNA nanostructures from ETDNA (Equilateral Triangle) to TPFDNA (Triangular Pyramid Frustum) was proposed for the first time. The inputs of aptamers and their relative targets made the DNA structure change from the “Open” to the “Closed” state, leading to the faradaic impedance changes as the output signals. The specific properties of excellent stability and specific rigid structure of 3D DNA nanostructures made the biosensor function as a regenerable, reusable and intelligent platform. The sensor exhibited excellent selectivity for IFN-γ detection with a wide linear range of 1.0 × 10−9 to 2.0 × 10−6 M and a low detection limit of 5.2 × 10−10 M. The distinctive features of DNA nanostructures make them potentially advantageous for a broad range of biosensing, bionanoelectronics, and therapeutic applications.
Co-reporter:Dawei Zhang, Jian Li, Jianbin Zheng
Materials Letters 2013 Volume 93() pp:99-102
Publication Date(Web):15 February 2013
DOI:10.1016/j.matlet.2012.11.054
A novel nanocomposite (PANI–TiC) prepared from polyaniline (PANI) and titanium carbide (TiC) was synthesized through an in situ chemical oxidative polymerization method. Detected by scanning electron microscopy and Fourier transform infrared spectra, morphologies and compositions of the nanocomposite were characterized. Experimental results of cyclic voltammetry (CV) indicated that PANI–TiC on PANI–TiC/GCE showed three pairs of redox peaks in acid medium and a pair of obvious redox peak in neutral medium. Electrocatalysis for ascorbic acid (AA) revealed good catalytic performance with the linear range from 50 μM to 2.25 mM and a sensitivity of 13.3 μA mM−1 cm−2 in neutral medium. This simple synthesis technique of preparing PANI–TiC nanocomposites showed great potential applications in sensor, catalysis, biomedical, environmental analysis, and so on.Highlights► We successfully synthesized the novel PANI–TiC nanocomposite by the in situ chemical oxidative polymerization method. ► The novel nanocomposite material showed good electrochemical properties and electrocatalytic. ► This is the first report to prepare the PANI–TiC using simple synthesis technique. ► The PANI–TiC nanocomposite has good synergic effect.
Co-reporter:Ruixiao Liu;Yahui Wei;Jianbin Zheng;Hongfang Zhang;Qinglin Sheng
Chinese Journal of Chemistry 2013 Volume 31( Issue 12) pp:1519-1525
Publication Date(Web):
DOI:10.1002/cjoc.201300487
Abstract
In this study, silver nanoparticles (AgNPs) were biosynthesized by Bacillus subtilis and used to construct a nonenzymatic hydrogen peroxide (H2O2) sensor. Scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy confirmed that the AgNPs were prepared successfully with spherical morphology. The electrochemical properties of the resulted sensor were investigated by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. It was found that the sensor exhibited good electrocatalytic activity towards H2O2 reduction with a wider linear range from 0.05 to 120 mmol·L−1, a detection limit of 8 µmol·L−1 and a fast response time less than 2 s. The sensor exhibited good selectivity for H2O2 determination in the presence of glucose, acetaminophen, ascorbic acid and uric acid.
Co-reporter:Hong-Fang Zhang, Jian-Bin Zheng, Rui-Xiao Liu
Chinese Chemical Letters 2013 Volume 24(Issue 10) pp:934-936
Publication Date(Web):October 2013
DOI:10.1016/j.cclet.2013.05.027
A new method for the formation of electroactive polyaniline (PANI) biocatalyzed by hemoglobin coupled with glucose oxidase in neutral medium on the polystyrene nanospheres (PS) modified glassy carbon electrode, was investigated. The bio-polymerized PANI formed on the PS was confirmed by the obvious increase of the diameter of the particles on the scanning electron microscopy image. The cyclic voltammetric behavior of the PANI was also investigated. PANI produced an oxidative peak at 0.28 V and a reductive peak at 0.23 V. Based on the glucose-dependent bio-polymerization, a new electrochemical protocol for the estimation of glucose was developed. The square wave voltammetric response of PANI deposited on the modified electrode increased linearly with glucose concentration in the range of 0.1–10.0 μmol/L. The efficient performance of hemoglobin-oxidase biocatalyzed polymerization of aniline provides a new concept for the synthesis of nanomaterials, and a general protocol for the development of the biosensors.The production of polyaniline bio-polymerized by hemoglobin-glucose oxidase at an electrode surface was investigated. The voltammetric response of polyaniline deposited on the electrode was found to be useful for the estimation of the concentration of glucose.
Co-reporter:Hongfang Zhang, Ruixiao Liu, Jianbin Zheng
Synthetic Metals 2013 Volume 167() pp:5-9
Publication Date(Web):1 March 2013
DOI:10.1016/j.synthmet.2013.01.020
The polyaniline (PANI)/Au nanocomposite was successfully fabricated through a seed-mediated strategy. And the hybrid nanostructure evaluated as a new material for cholesterol biosensor was demonstrated. UV–vis spectra proved the production of conductive PANI and the increase of the particle size of the Au nano-seeds. Scanning electron microscopic measurements displayed that the synthesized PANI/Au exhibited a spherical structure with dimensions of about 300 nm in diameter. Energy dispersive X-ray spectrogram demonstrated the ingredient of the composite. Cyclic voltammetry and electrochemical impedance spectroscopy investigation of the PANI/Au modified electrode indicated the good conductivity of the composite. Direct electron transfer of cholesterol oxidase (ChOx) was obtained in pH 7.0 phosphate buffer solution when ChOx was further immobilized on the PANI/Au modified electrode. This result showed that the PANI/Au nanocomposite was a good candidate for the development of the cholesterol biosensor. The biosensor displayed a response time of 3 s. Some common interferents like glucose and ascorbic acid did not cause interference due to the use of a low operating potential.Highlights► Polyaniline/Au nanocomposite was fabricated through a seed-mediated strategy. ► Direct electrochemistry of cholesterol oxidase was obtained. ► A rapid and interference-free cholesterol amperometric biosensor was developed.
Co-reporter:Yang Han, Jianbin Zheng, Sheying Dong
Electrochimica Acta 2013 90() pp: 35-43
Publication Date(Web):
DOI:10.1016/j.electacta.2012.11.117
Co-reporter:Bini Wang, Jianbin Zheng, Yaping He, Qinglin Sheng
Sensors and Actuators B: Chemical 2013 Volume 186() pp:417-422
Publication Date(Web):September 2013
DOI:10.1016/j.snb.2013.06.016
A sensitive biosensor for the determination of phenolic compounds was fabricated based on tyrosinase (Tyr), single-wall carbon nanotubes (SWCNTs) and polyaniline (PANI). The surface morphologies of complex films were characterized by the scanning electron microscopy (SEM) technique. Electrochemical investigation of the biosensor showed that it gave a linear response range of 2.5 × 10−7–9.2 × 10−5 and 2.5 × 10−7–4.7 × 10−4 M and detection limit of 8.0 × 10−8 and 6.0 × 10−8 M for catechol, caffeic acid, respectively. The biosensor also exhibits good sensitivity, repeatability and stability, and presents suitability to the quantification of catechol or caffeic acid in the tested samples.
Co-reporter:Qinglin Sheng, Ruixiao Liu and Jianbin Zheng
Nanoscale 2012 vol. 4(Issue 21) pp:6880-6886
Publication Date(Web):13 Sep 2012
DOI:10.1039/C2NR31830J
A novel route for controlled synthesis of Prussian blue nanospheres (PB NSs) with different sizes by using deep eutectic solvents (DES) as both solvent and template provider was demonstrated. The size-controlled PB NSs were obtained directly by the coordination of Fe(CN)64− ion with Fe3+ ion in the DES. The probable mechanism of formation of PB NSs was discussed based on the characterization results of UV-visible, X-ray diffraction, X-ray photoelectronic spectrum and transfer electron microscopy. Furthermore, the electrochemical and electrocatalytic properties of the synthesized PB NSs were investigated, and it has demonstrated that the PB NSs exhibited excellent catalytic activity for H2O2 reduction, and then extended this strategy to glucose sensing, by detecting H2O2 formed from the enzymatic reaction of glucose oxidase with its substrate glucose. The linear calibration range for glucose was from 0.9 μM to 0.12 mM, with a correlation coefficient of 0.998. The limit of detection was 0.3 μM and the sensitivity was 61.7 A cm−2 M−1. The present study provides a general platform for the controlled synthesis of novel nanomaterials in DES and can be extended to other optical, electronic and magnetic nanocompounds.
Co-reporter:Yaping He, Qinglin Sheng, Bin Liu, Jianbin Zheng
Electrochimica Acta 2012 Volume 66() pp:82-87
Publication Date(Web):1 April 2012
DOI:10.1016/j.electacta.2012.01.045
When free diffusing ammonia begins to dissolve into a reaction precursor solution, a gas/liquid interface formed. Three-dimensional (3D) network iron oxide (i-Fe3O4) was synthesized at the interface without the protection of any inert gas at room temperature. This is the first time ammonia vapor method be used to prepare nano iron oxide at a gas/liquid interface. Scanning electron microscope results of it indicated that 3D network i-Fe3O4 is an assembly of nanowires and its properties are quite similar to spherical Fe3O4 nanoparticle. Energy dispersive X-ray spectroscopy, X-ray diffraction and Fourier transform infrared spectra were used to confirm the presence of Fe3O4. Electrochemical methods were employed to investigate the sensing properties for the electrocatalytic oxidation of hydrazine hydrate at the i-Fe3O4/glassy carbon electrode (GCE). The sensor displayed a response time less than 2 s, a sensitivity of 152 μA mM−1 cm−2 and the linearity of 0.1 to 600 μM with a detection limit of 0.05 μM (S/N = 3).
Co-reporter:Aili Sun, Jianbin Zheng, Qinglin Sheng
Electrochimica Acta 2012 Volume 65() pp:64-69
Publication Date(Web):30 March 2012
DOI:10.1016/j.electacta.2012.01.007
In this paper, nickel was combined with multi-walled carbon nanotubes (Ni–MWNTs) to fabricate nanohybrid films on a conventional glassy carbon electrode using simultaneous electrodeposition of NiCl2 and the MWNTs in ionic liquids (ILs). The morphologies and elemental compositions of the nanohybrid films were investigated with scanning electron microscopy and energy dispersive spectroscopy. A novel non-enzymatic glucose sensor based on the Ni–MWNT nanohybrid film-modified glassy carbon electrode was described, and its electrochemical behaviors were investigated. The proposed sensor exhibited high electrocatalytic activity and good response to glucose. Under optimal conditions, the sensor showed high sensitivity (67.2 μA mM−1 cm−2), rapid response time (<2 s) and a low detection limit (0.89 μM; signal/noise ratio of 3). In particular, the upper glucose concentration limit produced a linear response of 17.5 mM. Thus, the Ni–MWNT nanohybrid films represent promising sensor materials for non-enzymatic glucose sensing in routine analyses.Graphical abstractCyclic voltammograms of Ni–MWNTs/GCE at different concentrations of glucose.Highlights► Ni –MWNT nanohybrid film was successfully synthesized and characterized by SEM and EDS. ► The mechanism of glucose at Ni –MWNT nanohybrid film was evaluated and the upper glucose concentration limit produced a linear response of 17.5 mM. ► Simple of preparation and good analytical response made nanohybrid films a promising sensor material for non-enzymatic glucose sensing in routine analysis.
Co-reporter:Yaping He, Jianbin Zheng and Qinglin Sheng
Analyst 2012 vol. 137(Issue 4) pp:1031-1038
Publication Date(Web):04 Jan 2012
DOI:10.1039/C2AN16032C
Unique monkshoodvine root–bark like morphology carbon materials (MLC) have been successfully synthesized under hydrothermal conditions. Utilizing the merits of high surface area and good electron conductivity of the MLC, a layered biosensor designed by assembling the MLC, hemoglobin (Hb) and gold nanoparticles was further developed. Scanning electron microscope and transmission electron microscope showed that the morphology of carbon materials can be successfully controlled simply by moderating the initiator amount of precursor and reaction temperature. The results indicated that the MLC was formed at the reaction condition of 5 mg Ferrocene + 6 mL CCl4 at 280 °C. Electrochemical methods, such as cyclic voltammetry and electrochemical impedance spectroscopy, were used to characterize the layered biosensor and its application for sensitive detection of hydrogen peroxide (H2O2). Under optimized experimental condition, the linear range for the determination of H2O2 was 0.06 μM to 1.6 mM with a detection limit of 0.03 μM (S/N = 3). Furthermore, the biosensor also showed a fast response (within 2 s) and high stability.
Co-reporter:Hongfang Zhang, Ruixiao Liu and Jianbin Zheng
Analyst 2012 vol. 137(Issue 22) pp:5363-5367
Publication Date(Web):10 Sep 2012
DOI:10.1039/C2AN36075F
A bienzyme electrode for the determination of cholesterol was prepared by the co-immobilization of cholesterol oxidase and alkaline phosphatase (ALP) on the carbon nanotubes modified electrode surface. The parameters influenced the performance of the bienzyme electrode such as the pH of the base solution; the concentration of DPP and the incubation time, were optimized. A linear calibration graph in the 0.05–2.0 mM concentration range with the sensitivity of 4.65 μA mM−1 was obtained. In addition, this work provides a new interferent-depleted method and universal protocol for the design of multi-enzyme biosensors.
Co-reporter:Yaping He, Jianbin Zheng and Sheying Dong
Analyst 2012 vol. 137(Issue 20) pp:4841-4848
Publication Date(Web):22 Aug 2012
DOI:10.1039/C2AN35672D
A facile, one-pot ultrasonic electrochemical method to synthesize hierarchical cobalt (Co)-nanoflowers on petalage-like graphene (GE) was developed. The hybrid microstructures were successfully evaluated as a new material for highly sensitive determination of hydrazine (N2H4). Scanning electron microscopic measurements displayed that the synthesized Co–GE exhibited a related hierarchical structure of a petalage-like GE homogeneous distribution as a matrix for the growth of smooth nanosheets-assembled Co nanoflowers. Co–GE was confirmed by energy dispersive X-ray spectrograms. Electrochemical methods were adopted to characterize the sensing properties of Co–GE towards the electrocatalytic oxidation of N2H4 at 0.15 V in 0.1 M pH 7.0 sodium phosphate buffered saline. The sensor displayed a broad linearity of 0.25–370 μM and 370 μM to 2.2 mM with a relatively low detection limit of 0.1 μM (S/N = 3) and a response time of less than 3 s. Furthermore, the sensor showed outstanding sensitivity and reproducibility.
Co-reporter:Qi Wang, Jianbin Zheng, Hongfang Zhang
Journal of Electroanalytical Chemistry 2012 Volume 674() pp:1-6
Publication Date(Web):1 June 2012
DOI:10.1016/j.jelechem.2012.02.009
A novel formaldehyde (HCHO) sensor fabricated by electrodeposition of AgPd alloy nanoparticles (NPs) on chitosan (Ch)–ionic liquid (IL, i.e., 1-octyl-3-methylimidazolium hexafluorophosphate, OMIM·PF6) films is developed. A scanning electron micrograph of the AgPd/Ch–IL composite film shows a uniform distribution of spherical AgPd NPs with particle sizes of 30–60 nm. Energy-dispersive X-ray measurements indicate that the mass ratio of Pd and Ag in the alloy is 21:5. Cyclic voltammetric studies show that an electrode coated with the AgPd/Ch–IL composite film exhibits high electrocatalytic activity and stability towards electrooxidation of HCHO. The HCHO sensor exhibits linear behavior in the concentration range from 0.060 mM to 20 mM, allowing quantitative analysis of HCHO with a detection limit of 0.022 mM (S/N = 3).Highlights► A HCHO sensor fabricated by electrodeposition of AgPd alloy is proposed. ► The HCHO sensor has high catalytic activity towards the electrooxidation of HCHO. ► The HCHO sensor has good tolerance to CO poisoning. ► The HCHO sensor has a low overpotential for the oxidation of formaldehyde.
Co-reporter:Hongfang Zhang, Jianbin Zheng
Talanta 2012 Volume 93() pp:67-71
Publication Date(Web):15 May 2012
DOI:10.1016/j.talanta.2012.01.037
A baicalin multi-wall carbon nanotubes (BaMWCNT) modified glassy carbon electrode (GCE) for the sensitive determination of hydroxylamine was described. The BaMWCNT/GCE with dramatic stability was firstly fabricated with a simple adsorption method. And it showed excellent catalytic activity toward the electrooxidation of hydroxylamine. The amperometric response at the BaMWCNT/GCE modified electrode increased linearly to hydroxylamine concentrations in the range of 0.5 μM to 0.4 mM with a detection limit of 0.1 μM. The modified electrode was applied to detection hydroxylamine in the tap water, and the average recovery for the standards added was 96.0%.Highlights► A new modified electrode for the sensitive determination of hydroxylamine. ► Only 5 s was needed for the modification of baicalin and no dried procedure was needed. ► The first report on the electrocatalytic activity of baicalin. ► Lowest detection limit in 8 modified electrodes.
Co-reporter:Hongye Zhao;Qinglin Sheng;Jianbin Zheng
Microchimica Acta 2012 Volume 176( Issue 1-2) pp:177-184
Publication Date(Web):2012 January
DOI:10.1007/s00604-011-0699-8
We report on the direct electrochemistry and electrocatalysis of horseradish peroxidase immobilized on a composite matrix composed of polystyrene, multiwalled carbon nanotubes and Nafion on a gold electrode. The modified electrode was characterized by scanning electron microscopy, UV–vis and FT-IR spectroscopy. A pair of well-defined redox peak of HRP is obtained with the formal potential at −0.400 V at pH 7.0. The electron transfer rate constant is 1.15 s−1. The modified electrode exhibits excellent electrocatalytic activity to the reduction of H2O2, with a linear response in the 0.5 μM to 0.82 mM concentration range and a detection limit at 0.16 μM (S/N = 3). The apparent Michaelis-Menten constant is 0.66 mM. The modified electrode is biocompatible and conceived to serve as a versatile platform for the fabrication of electrochemical biosensors.
Co-reporter:Ningqiang Qiao;Jianbin Zheng
Microchimica Acta 2012 Volume 177( Issue 1-2) pp:103-109
Publication Date(Web):2012/04/01
DOI:10.1007/s00604-011-0756-3
We report on a nonenzymatic glucose sensor based on a glassy carbon electrode that was electrochemically modified with a nanocomposite prepared from nickel hydroxide and graphene. Scanning electron microscopy revealed that the nickel hydroxide in the nanocomposite was present in the form of a nanostructure of three-dimensional spheres that were assembled by many densely arranged nanosheets. The electrocatalytic activity of the electrode toward the oxidation of glucose was investigated by chronoamperometry. The current response was linearly related to the glucose concentration in the range from 1 to 10 μM, with a sensitivity of 494 μA mM–1 cm–2 and a correlation coefficient of 0.9990, and a second range (from 10 to 1000 μM with a sensitivity of 328 μA mM–1 cm–2 and a correlation coefficient of 0.9990). The detection limit was 0.6 μM at a signal-to-noise ratio of 3, and the response time was as short as 2 s.
Co-reporter:Aili Sun, Hongye Zhao, Jianbin Zheng
Talanta 2012 Volume 88() pp:259-264
Publication Date(Web):15 January 2012
DOI:10.1016/j.talanta.2011.09.067
The Zn–Sn nanoparticles/multiwall carbon nanotubes (Zn–SnNPs/MWNTs) nanocomposite film was prepared by electrodeposition of ZnCl2 and SnCl2 on MWNTs simultaneously in Ethaline ionic liquids. Then, based on immobilizing hemoglobin (Hb) within a novel Zn–SnNPs/MWNTs nanocomposite film (Hb/Zn–SnNPs/MWNTs), a novel hydrogen peroxide (H2O2) biosensor was constructed. Meantime, the morphology of the Zn–SnNPs and analytical characteristics of the biosensor were investigated. A high density and well-distributed Zn–SnNPs spheres with an average diameter of 120 nm was observed by field emission scanning electron microscopy. The voltammetric results of the biosensor showed a pair of well-defined and quasi-reversible redox peaks of Hb with a formal potential (E0′) of −0.40 V and a peak-to-peak separation (ΔEp) of 0.086 V. Moreover, the biosensor exhibited an excellent electrocatalytic activity to H2O2 with a KM value of 0.379 mM; the reduction peak currents of Hb on the Hb/Zn–SnNPs/MWNTs/GCE were linearly related to H2O2 in the range from 0.5 to 840 μM with a correlation coefficient of 0.9984 and a detection limit of 0.11 μM (S/N = 3). Results demonstrated that Zn–SnNPs/MWNTs nanocomposite film was promising a new platform for the construction of H2O2 biosensors and provided a way to develop other biologic active materials in ionic liquids.Highlights► Electrodeposition of Zn–Sn nanocomparticles in deep eutectic solvents on the substance of MWNTs was realized and used to realize direct electron transfer in the bioelectrochemistry for the first time. ► The Hb/Zn–SnNPs/MWCNTs modified electrode were linearly related to H2O2 concentration in a wider linearity range from 0.5 to 840 μM and a lower detection limit of 0.11 μM. ► The present biosensor provide a good electrochemical sensing platform for redox proteins and has wide applications in biosensors and biocatalysis.
Co-reporter:Yaping He, Qinglin Sheng, Jianbin Zheng
Sensors and Actuators B: Chemical 2012 Volumes 166–167() pp:89-96
Publication Date(Web):20 May 2012
DOI:10.1016/j.snb.2011.12.092
Platinum nanomaterials were synthesized through a double-template electrochemical deposition. Scanning electron microscope, energy dispersive X-ray spectroscopy and X-ray diffraction was used to investigate the morphology and ingredient changes during the fabrication process of platinum nanoparticles (PtNPs)/nanozinc oxide (nanoZnO) modified glassy carbon electrode (GCE). Electrochemical methods were adopted to characterize the sensing properties of the proposed modified electrode towards hydrogen peroxide (H2O2) and hydrazine hydrate (N2H4). The results indicated that the PtNPs/nanoZnO/GCE showed synergistic electrochemical effect for electrocatalytic reduction of H2O2 and electrocatalytic oxidation of N2H4. Take N2H4 sensing for example, the modified electrode displayed a fast response (<4 s), high sensitivity (110 μA mM−1 cm−1) and broad linear in the range from 0.5 to 1300 μM and 1300 to 6000 μM with a relatively low detection limit of 0.2 μM (S/N = 3). Zero current potentiometry was used for in situ probing the changes of the interfacial potential during the electrocatalytic oxidation of N2H4 on the modified electrode.
Co-reporter:Jianbin Zheng, Yaping He, Qinglin Sheng and Hongfang Zhang
Journal of Materials Chemistry A 2011 vol. 21(Issue 34) pp:12873-12879
Publication Date(Web):26 Jul 2011
DOI:10.1039/C1JM11707F
Taking advantages of the striking properties of both self-assembly and biocatalysis, a highly sensitive glucose electrochemical biosensor was proposed by using DNA–GE as biocatalysis target-guide to deposit Au nanoparticles (AuNPs). AuNPs interacted with thiol and amino groups of DNA strands, which make the reaction much easier and faster. Furthermore, the proposed AuNPs/glucose oxidase (GOx)/DNA–GE/glassy carbon (GC) modified electrode achieved the direct electrochemistry and electrocatalysis of GOx. The growth of AuNPs was confirmed by scanning electron microscopy and electrochemical methods. The characterizations of the electrode modified after each assembly step and the content of AuNPs on the electrode surfaces during the growth process were investigated by cyclic voltammetry. The amount of AuNPs was relative to the amount of glucose oxidized accompanying with the biocatalytic process of GOx. The biosensor showed a linearity with glucose concentration in the range of 0.8–50 μM with a detection limit of 0.3 μM (S/N = 3). The sensitivity was 2.4 × 104 μA mM−1. The combination of self-assembly and biocatalysis offers the new design of enzymatic biosensors with potential applications in direct electrochemistry and biocatalysis.
Co-reporter:Yaping He, Qinglin Sheng, Jianbin Zheng, Minzhi Wang, Bin Liu
Electrochimica Acta 2011 Volume 56(Issue 5) pp:2471-2476
Publication Date(Web):1 February 2011
DOI:10.1016/j.electacta.2010.11.020
Magnetite–graphene (Fe3O4–GE) was prepared via a simple effective chemical precipitation method, followed by the chemical reduction with hydrazine. Fe3O4–GE was characterized by Raman spectroscopy, transmission electron microscope, X-ray powder diffraction and electrochemical methods. A hydrogen peroxide (H2O2) biosensor was structured by immobilizing hemoglobin (Hb) into Fe3O4–GE for the first time. UV–vis and Fourier transform infrared spectra were employed to characterize Hb retained original structure in the resulting Hb–Fe3O4–GE membrane. Electrochemical investigation of the biosensor showed a pair of well-defined, quasi-reversible redox peaks with Epa = −0.285 V and Epc = −0.363 V (vs. SCE) in phosphate buffer solution (0.1 mol/L, pH 7.0) at the scan rate of 100 mV/s. The Hb–Fe3O4–GE showed a better synergistic electrochemical effect for the reduced process of H2O2. The biosensor displayed a fast response time (<3 s) and broad linear response to H2O2 in the range from 1.50 to 585 μmol/L with a relatively low detection limit of 0.5 μmol/L (S/N = 3). Moreover, the biosensor could be applied in practical analysis and exhibit good reproducibility and long-term stability.
Co-reporter:Zuchao Meng, Jianbin Zheng, Qinglin Sheng, Xiaohui Zheng
Analytica Chimica Acta 2011 Volume 689(Issue 1) pp:47-51
Publication Date(Web):9 March 2011
DOI:10.1016/j.aca.2011.01.028
Thulium hexacyanoferrate (TmHCF) nanoparticles (NPs) were in situ synthesized within the chitosan film on the electrode surface by a biocatalyzed reaction. The properties of the obtained nanoparticles are characterized with scanning electron microscope (SEM) and energy-dispersive X-ray (EDX). The optimized conditions for the formation of TmHCF NPs were 16 mM Fe(CN)63− and 1.5 mM Tm3+ with an accumulation time of 20 min. Based on process of in situ synthesis of TmHCF NPs, a novel biosensor for glucose was designed, and there is a linear relationship between the current response of TmHCF NPs and glucose concentration. The linear range for glucose detection was 0.02–0.4 mM (r = 0.9975, n = 5) and 0.4–13.6 mM (r = 0.9935, n = 10) and the detection limit was 6 μM at a signal-to-noise ratio of 3.
Co-reporter:Na Tang, Jianbin Zheng, Qinglin Sheng, Hongfang Zhang and Ruixiao Liu
Analyst 2011 vol. 136(Issue 4) pp:781-786
Publication Date(Web):13 Dec 2010
DOI:10.1039/C0AN00379D
A novel H2O2 sensor based on enzymatically induced deposition of electroactive polyaniline (PANI) at a horseradish peroxide (HRP)/aligned single-wall carbon nanotubes (SWCNTs) modified Au electrode is fabricated, and its electrochemical behaviors are investigated. Electrochemical impedance spectroscopy of the sensor confirmed the formation of PANI on SWCNTs through the HRP catalytic reaction. Cyclic voltammograms of PANI/HRP/SWCNTs modified Au electrodes showed a pair of well-defined redox peaks of PANI with reduction peak potentials of 0.211 and oxidation peak potentials of 0.293 V in 0.1 M HOAc-NaOAc (pH 4.3) solution. The oxidation peak current response of PANI is linearly related to H2O2 concentration from 2.5 μM to 50.0 μM with a correlation coefficient of 0.9923 and a sensitivity of 200 μA mM−1. The detection limit is determined to be 0.9 μM with a signal-to-noise ratio of 3. Thus, the synergistic performance of the enzyme, the highly efficient polymerization of PANI, and the templated deposition of SWCNTs provided an extensive platform for the design of novel electrochemical biosensors.
Co-reporter:Hongfang Zhang, Ruixiao Liu, Qinglin Sheng, Jianbin Zheng
Colloids and Surfaces B: Biointerfaces 2011 Volume 82(Issue 2) pp:532-535
Publication Date(Web):1 February 2011
DOI:10.1016/j.colsurfb.2010.10.012
This paper reported the enzymatic deposition of Au nanoparticles (AuNPs) on the designed 3-mercapto-propionic acid/glucose oxidase/chitosan (MPA/GOD/Chit) modified glassy carbon electrode and its application in glucose detection. Chit served as GOD immobilization matrix and interacted with MPA through electrostatic attraction. AuNPs, without nano-seeds presented on the electrode surface, was produced through the glucose oxidase catalyzed oxidation of glucose. The mechanism of production of AuNPs was confirmed to be that enzymatic reaction products H2O2 in the solution reduce gold complex to AuNPs. The characterizations of the electrode modified after each assembly step was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Scanning electron microscopy showed the average particle size of the AuNPs is 40 nm with a narrow particle size distribution. The content of AuNPs on the electrode surfaces was measured by differential pulse stripping voltammetry. The electrochemical signals on voltammogram showed a linear increase with the glucose concentration in the range of 0.010–0.12 mM with a detection limit of 4 μM. This provided a method to the determination of glucose.
Co-reporter:Ruifang Gao;Jianbin Zheng;Xiaohui Zheng
Microchimica Acta 2011 Volume 174( Issue 3-4) pp:273-280
Publication Date(Web):2011 September
DOI:10.1007/s00604-011-0617-0
We describe an ionic liquid modified electrode (CPE-IL) for sensing hydrogen peroxide (HP) that was modified by the layer-by-layer technique with myoglobin (Mb). In addition, the surface of the electrode was modified with CeO2 nanoparticles (nano-CeO2) and hyaluronic acid. UV-vis and FTIR spectroscopy confirmed that Mb retains its native structure in the composite film. Scanning electron microscopy showed that the nano-CeO2 closely interact with Mb to form an inhomogeneously distributed film. Cyclic voltammetry reveals a pair of quasi-reversible redox peaks of Mb, with the cathodic peak at −0.357 V and the anodic peak at −0.269 V. The peak separation (ΔEp) and the formal potential (E0′) are 88 mV and −0.313 V (vs. Ag/AgCl), respectively. The Mb immobilized in the modified electrode displays an excellent electrocatalytic activity towards HP in the 0.6 to 78.0 μM concentration range. The limit of detection is 50 nM (S/N = 3), and then the Michaelis-Menten constant is 71.8 μM. We believe that such a composite film has potential to further investigate other redox proteins and in the fabrication of third-generation biosensors.
Co-reporter:Hongfang Zhang, Zuchao Meng, Qi Wang, Jianbin Zheng
Sensors and Actuators B: Chemical 2011 Volume 158(Issue 1) pp:23-27
Publication Date(Web):15 November 2011
DOI:10.1016/j.snb.2011.04.057
A novel glucose biosensor based on biomediated gold nanoparticles (AuNPs)–glucose oxidase (GOD)–carbon nanotubes–polyvinyl alcohol biocomposite film was fabricated for the first time. Direct electrochemistry of GOD in the film was obtained, proved by one pair of well-defined, quasi-reversible redox peaks with the formal potential of −0.504 V in pH 7.0 phosphate buffer solution at the scan rate of 100 mV s−1. And the electron transfer rate constant of the direct electron communication between GOD and the electrode was calculated to be 2.2 s−1. The biomediated AuNPs play an important role in facilitating the electron exchange between the electroactive center of GOD and the electrode. Furthermore, the fabricated electrode displayed a linear amperometric response in the glucose concentration range from 0.5 to 8.0 mM with a relatively high sensitivity of 16.6 μA mM−1 cm−2. Therefore, the AuNPs based biosensor described here provides a different mode to design electrochemical devices.
Co-reporter:Zuchao Meng;Bin Liu;Jianbin Zheng;Qinglin Sheng;Hongfang Zhang
Microchimica Acta 2011 Volume 175( Issue 3-4) pp:251-257
Publication Date(Web):2011 December
DOI:10.1007/s00604-011-0688-y
We describe a modified glassy carbon electrode (GCE) for the sensitive determination of nitrite in waste water samples. The GCE was modified by electrodeposition of cobalt oxide nanoparticles on multi-walled carbon nanotubes (MWCNTs) deposited on a conventional GCE. Scanning electron microscopy and electrochemical techniques were used for the characterization of the composite material which is very uniform and forms a kind of nanoporous structure. Electrochemical experiments showed that the modified electrode exhibited excellent electrocatalytic properties for nitrite. Amperometry revealed a good linear relationship between peak current and nitrate concentration in the 0.5 to 250 μM range with a detection limit of 0.3 μM (S/N = 3). The method has been applied to the amperometric detection of nitrite. The modified electrode displays good storage stability, reproducibility, and selectivity for a promising practical application.
Co-reporter:Qing-Lin Sheng, Jian-Bin Zheng, Xiao-Dong Shang-Guan, Wang-Hua Lin, Yuan-Yao Li, Rui-Xiao Liu
Electrochimica Acta 2010 Volume 55(Issue 9) pp:3185-3191
Publication Date(Web):30 March 2010
DOI:10.1016/j.electacta.2009.12.101
The combination of porous carbon nanofiber (PCNF) and room-temperature ionic liquid (RTIL) provided a suitable microenvironment for heme-proteins to transfer electron directly. Hemoglobin, myoglobin, and cytochrome c incorporated in PCNF/RTIL films exhibited a pair of well-defined, quasi-reversible cyclic voltammetric peaks at about −0.28 V vs. SCE in pH 7.0 buffers, respectively, characteristic of the protein heme Fe(III)/Fe(II) redox couples. The cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the modified electrode. The heme/PCNF/RTIL/CHIT films were also characterized by UV–vis spectroscopy, indicating that heme-proteins in the composite film could retain its native structure. Oxygen, hydrogen peroxide, and nitrite were catalytically reduced at the heme/PCNF/RTIL/CHIT film modified electrodes, showing the potential applicability of the films as the new type of biosensors or bioreactors based on direct electrochemistry of the redox proteins.
Co-reporter:Xiaodong Shangguan; Dr. Jianbin Zheng;Hongfang Zhang ;Hongsheng Tang
Chinese Journal of Chemistry 2010 Volume 28( Issue 10) pp:1890-1896
Publication Date(Web):
DOI:10.1002/cjoc.201090315
Abstract
Multi-walled carbon nanotubes (MWNTs) were dispersed in the ionic liquid [BMIM][BF4] to form a uniform black suspension. Based on it, a novel glucose oxidase (GOx)-hyaluronic (HA)-[BMIM][BF4]-MWNTs/GCE modified electrode was fabricated. UV-vis spectroscopy confirmed that GOx immobilized in the composite film retained its native structure. The experimental results of EIS indicated MWNTs, [BMIM][BF4] and HA were successfully immobilized on the surface of GCE and [BMIM][BF4]-MWNTs could obviously improve the diffusion of ferricyanide toward the electrode surface. The experimental results of CV showed that a pair of well-defined and quasi-reversible peaks of GOx at the modified electrode was exhibited, and the redox reaction of GOx at the modified electrode was surface-confined and quasi-reversible electrochemical process. The average surface coverage of GOx and the apparent Michaelis-Menten constant were 8.5×10−9 mol/cm2 and 9.8 mmol/L, respectively. The cathodic peak current of GOx and the glucose concentration showed linear relationship in the range from 0.1 to 2.0 mmol/L with a detection limit of 0.03 mmol/L (S/N=3). As a result, the method presented here could be easily extended to immobilize and obtain the direct electrochemistry of other redox enzymes or proteins.
Co-reporter:Yaping He; Dr. Jianbin Zheng;Kuangtian Li;Qinglin Sheng ;Ningqiang Qiao
Chinese Journal of Chemistry 2010 Volume 28( Issue 12) pp:2507-2512
Publication Date(Web):
DOI:10.1002/cjoc.201190030
Abstract
A room temperature ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate functionalized graphene (GE) was prepared and a hydrogen peroxide (H2O2) biosensor was fabricated by immobilizing hemoglobin (Hb) into the IL-GE composite film. UV-visible and Fourier transform infrared spectra of the composite film indicated that Hb retained its native structure in the film. Electrochemical investigation of the biosensor showed a pair of well-defined, quasi-reversible redox peaks with Epa=−0.209 V and Epc= −0.302 V (vs. SCE) in pH 7.0 phosphate buffer solution at the scan rate of 100 mV/s. To the reduction of H2O2, the biosensor had a good linear range from 8.0×10−7 to 1.8×10−4 mol/L with a detection limit of 3.0×10−7 mol/L. The apparent Michaelis-Menten constant KappM was estimated to be 3.4×10−5 mol/L.
Co-reporter:Qinglin Sheng, Jian Wang, Jianbin Zheng, Ziqin Xu, Hongfang Zhang
Biosensors and Bioelectronics 2010 Volume 25(Issue 9) pp:2071-2077
Publication Date(Web):15 May 2010
DOI:10.1016/j.bios.2010.02.002
An ultrasensitive assay for electrical biosensing of syphilis DNA was proposed by using target-guided formation of polyaniline (PANI) based on an enzymatically catalyzed method. The sensitive biodetection relies on the DNA hybridization and biotin–streptavidin interaction. After coupling of biotinylated catalase with streptavidin-modified hybrids, a head-to-tail structure of PANI templated by hybridized DNA was formed. The current response of PANI was linearly related to target DNA concentration between 1.0 pM and 1.0 nM with a correlation coefficient of 0.998. The detection limit was determined to be 0.5 pM with the signal-to-noise ratio of 3. The synergistic performances of DNA hybridization, strong biotin–streptavidin binding ability, and highly efficient polymerization provide a general platform for simple, highly sensitive and selective biosensor for the detection of the specific polA gene fragment of T. pallidum. It is expected that the proposed biosensor holds great promise for diagnosing disease in practice.
Co-reporter:Ruifang Gao, Jianbin Zheng
Electrochemistry Communications 2009 Volume 11(Issue 7) pp:1527-1529
Publication Date(Web):July 2009
DOI:10.1016/j.elecom.2009.05.046
Poly-anionic deoxyribonucleic acid (DNA) was accumulated on the positively charged surface of carbon ionic liquid electrode (CILE) with N-butylpyridinium hexafluorophosphate (BPPF6) as binder, and then myoglobin (Mb) was immobilized onto the DNA film by electrostatic interaction to form Mb/DNA/CILE electrode. The direct electrochemistry of Mb was then investigated in detail. A pair of well-defined, quasi-reversible cyclic voltammetric peaks of Mb was obtained with the formal potentials (E0′) at −0.304 V (vs. SCE) in phosphate buffer solution (PBS, pH 7.0). The Mb/DNA/CILE electrode showed excellent electrocatalytic activity to H2O2 and trichloroacetic acid (TCA) in the range of 1.0–160 μmol/L and 0.5–40.0 mmol/L, respectively. The apparent Michaelis–Menten constants (KM) toward H2O2 and TCA were calculated as 0.42 and 0.82 mmol/L. So, the DNA/CILE had potential to study other proteins.
Co-reporter:Ruifang Gao, Jianbin Zheng
Electrochemistry Communications 2009 Volume 11(Issue 3) pp:608-611
Publication Date(Web):March 2009
DOI:10.1016/j.elecom.2008.12.060
A novel nanocomposite was fabricated by three steps. In the first step, a chemical route was adopted to functionalization single-walled carbon nanotube (SWNT) with a new amine-terminated ionic liquid (NH2-IL) to form IL-SWNT composite. In the second step, gold nanoparticle (GNP) was electrodeposited onto IL-SWNT to prepare GNP-IL-SWNT nanocomposite. In the last step, IL-GNP-IL-SWNT nanocomposite was obtained by self-assembly NH2-IL on GNP. Glucose oxidase (GOD) was assembled on this novel composite through ionic interaction and achieved its direct electrochemistry. A pair of well-shaped voltammetric peaks was observed with the formal potentials (E0′) at −0.501 V. The GOD modified electrode also exhibited an excellent electrocatalytic activity to the reduction of glucose with a detection limit of 0.8 μmol/L (S/N = 3). The apparent Michaelis–Menten constant (Kmapp) was estimated to be 0.022 mM. This protocol had potential application to fabricate the third-generation biosensor.
Co-reporter:Yan Liang, Wei Cao, Wei-jun Chen, Xue-hong Xiao, Jian-bin Zheng
Food Chemistry 2009 Volume 114(Issue 4) pp:1537-1541
Publication Date(Web):15 June 2009
DOI:10.1016/j.foodchem.2008.11.024
A sensitive and accurate method for simultaneous separation and determination of four phenolic compounds, including caffeic acid, p-coumaric acid, ferulic acid, and hesperetin in Chinese citrus honey by high performance liquid chromatography using electrochemical detection (HPLC-ECD) has been established. Chromatographic separation was performed using a reversed phase column and methanol/4% (v/v) aqueous acetic acid as the mobile phase. The detection and quantification limits of the four compounds with ECD were 6–14 times greater than those obtained with diode-array detection (DAD). All calibration curves of the four phenolic compounds showed good linearity (r ⩾ 0.9994) within the test ranges, 1.10–66 μg/ml, 0.35–70 μg/ml, 0.16–16 μg/ml and 0.03–10 μg/ml, respectively. The recoveries ranged from 98.9% to 100.3%. The extraction process was very simple, because of the dissolution of honey only involving water. Taken together, the application of ECD in honey determination leads to a significant improvement in the quantification of phenolic compounds, whereby paying the way for the establishment of a better quality control of citrus honey.
Co-reporter:Rong Li;Yan Wang;Guo Liang Chen;Xiao Gang Wang
Chromatographia 2009 Volume 70( Issue 5-6) pp:731-737
Publication Date(Web):2009 September
DOI:10.1365/s10337-009-1219-4
A glutamic acid-bonded silica (Glu-silica) stationary phase with cation-exchange properties was synthesized using l-glutamic acid as ligand and silica gel as matrix. The effects of solution pH value, salt concentration and metal ion on the retention of proteins were examined. The standard protein mixture was separated with a prepared chromatographic column and an iminodiacetic acid column, and compared. The influence of the binding capacity of an immobilized metal ion on the complexation of metal chelate column was studied. The results indicate that the obtained column displays cation-exchange characteristic and better separation ability for proteins. As fixing metal ion on the Glu-silica column, retention of proteins on the column is a cooperative interaction of metal chelate and cation-exchange. The stationary phase shows the typical metal chelate properties with the increase of the sorption capacity of immobilized metal ion.
Co-reporter:Qinglin Sheng, Jianbin Zheng
Biosensors and Bioelectronics 2009 Volume 24(Issue 6) pp:1621-1628
Publication Date(Web):15 February 2009
DOI:10.1016/j.bios.2008.08.029
A novel method based on covalent attachment of two enzymes, glucose oxidase (GOD) and horseradish peroxide (HRP), onto carboxylic-derived multiwalled carbon nanotubes (MWNTs) for the deposition of electroactive polyaniline (PANI) under ambient conditions is described. Ultraviolet–visible spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and transmission electron microscopy were used to characterize the assembling of bienzyme and the morphology of PANI|MWNTs. Under the bienzyme biocatalytic condition, a head-to-tail structure of PANI templated by MWNTs was formed. The voltammetric characteristics of the resulting biosensor were investigated by cyclic voltammetry in the presence of glucose. The current response of PANI was linearly related to glucose concentration between 0.05 and 12.0 mM with a correlation coefficient of 0.994. The synergistic performance of bienzyme, highly efficient polymerization, and templated deposition provide a general platform for the synthesis of nanowires and nanocircuits, the construction of bioelectronic devices, and the design of novel biosensors.
Co-reporter:Ya Zhang, Jianbin Zheng
Electrochimica Acta 2008 Volume 54(Issue 2) pp:749-754
Publication Date(Web):30 December 2008
DOI:10.1016/j.electacta.2008.06.066
A robust and effective composite film combined the benefits of room temperature ionic liquid (RTIL), chitosan (Chi) and multi-wall carbon nanotubes (MWNTs) was prepared. Cytochrome c (Cyt c) was successfully immobilized on glassy carbon electrode (GCE) surface by entrapping in the composite film. Direct electrochemistry and electrocatalysis of immobilized Cyt c were investigated in detail. A pair of well-defined and quasi-reversible redox peaks of Cyt c was obtained in 0.1 mol L−1 pH 7.0 phosphate buffer solution (PBS), indicating the Chi–RTIL–MWNTs film showed an obvious promotion for the direct electron transfer between Cyt c and the underlying electrode. The immobilized Cyt c exhibited an excellent electrocatalytic activity towards the reduction of H2O2. The catalysis current was linear to H2O2 concentration in the range of 2.0 × 10−6 to 2.6 × 10−4 mol L−1, with a detection limit of 8.0 × 10−7 mol L−1 (S/N = 3). The apparent Michaelis–Menten constant (Km) was calculated to be 0.45 ± 0.02 mmol L−1. Moreover, the modified electrode displayed a rapid response (5 s) to H2O2, and possessed good stability and reproducibility. Based on the composite film, a third-generation reagentless biosensor could be constructed for the determination of H2O2.
Co-reporter:Ya Zhang, Jianbin Zheng
Electrochemistry Communications 2008 Volume 10(Issue 9) pp:1400-1403
Publication Date(Web):September 2008
DOI:10.1016/j.elecom.2008.07.022
A novel biocomposite film based on hyaluronic acid (HA) and hydrophilic room temperature ionic liquid 1-ethyl-3-methyl-imidazolium tetrafluoroborate ([EMIM][BF4]) was explored. Here, HA was used as a binder to form [EMIM][BF4]-HA composite film and help [EMIM][BF4] to attaching on glass carbon electrode (GCE) surface, while doping [EMIM][BF4] in HA can effectively reduce the electron transfer resistance of HA. The composite film can be readily used as an immobilization matrix to entrap myoglobin (Mb). A pair of well-defined and quasi-reversible redox peaks of Mb was obtained at the Mb-[EMIM][BF4]-HA composite film modified GCE (Mb-[EMIM][BF4]-HA/GCE) through direct electron transfer between Mb and the underlying electrode. The Mb-[EMIM][BF4]-HA/GCE showed an excellent electrocatalytic activity toward the reduction of H2O2. Based on the [EMIM][BF4]-HA biocomposite film, a third-generation reagentless biosensor could be constructed for the determination of H2O2.
Co-reporter:Qing-Lin SHENG;Yu SHEN;Hong-Fang ZHANG ;Jian-Bin ZHENG
Chinese Journal of Chemistry 2008 Volume 26( Issue 7) pp:1244-1250
Publication Date(Web):
DOI:10.1002/cjoc.200890226
Abstract
The direct electrochemistry of glucose oxidase (GOx) immobilized on a composite matrix based on chitosan (CHIT) and Au nanoparticles (Au NP) underlying on a glassy carbon electrode was achieved. The cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the modified electrode. In deaerated buffer solutions, the cyclic voltammetry of the composite films of GOx-Au NP-CHIT showed a pair of well-behaved redox peaks that were assigned to the redox reaction of GOx, confirming the effective immobilization of GOx on the composite film. The electron transfer rate constant was estimated to be 15.6 s−1, indicating a high electron transfer between the GOx redox center and electrode. The combination of CHIT and Au NP also promoted the stability of GOx in the composite film and retained its bioactivity, which might have the potential application to glucose determination. The calculated apparent Michaelis-Menten constant was 10.1 mmol·L−1. Furthermore, the proposed biosensor could be used for the determination of glucose in human plasma samples.
Co-reporter:Qing-Lin Sheng;Hao Yu;Jian-Bin Zheng
Journal of Solid State Electrochemistry 2008 Volume 12( Issue 9) pp:1077-1084
Publication Date(Web):2008 September
DOI:10.1007/s10008-007-0437-7
A kind of erbium hexacyanoferrate (ErHCF)-modified carbon ceramic electrodes (CCEs) fabricated by mechanically attaching ErHCF samples to the surface of CCEs derived from sol–gel technique was proposed. The resulting modified electrodes exhibit well-defined redox responses with the formal potential of +0.215 V [vs saturated calomel electrode (SCE)] at a scan rate of 20 mV s−1 in 0.5 M KCl (pH 7) solution. The voltammetric characteristics of the ErHCF-modified CCEs were investigated by voltammetry. Attractively, the ErHCF-modified CCEs presented good electrocatalytic activity with a marked decrease in the overvoltage about 400 mV for l-cysteine oxidation. The calibration plot for l-cysteine determination was linear at 5.0 × 10−6–1.3 × 10−4 M with a linear regression equation of I(A) = 0.558 + 0.148c (μM) (R2 = 0.9989, n = 20), and the detection limit was 2 × 10−6 M (S/N = 3). At last, the ErHCF-modified CCEs were used for amperometric detection of l-cysteine in real samples.
Co-reporter:Ya Zhang, Jianbin Zheng
Talanta 2008 Volume 77(Issue 1) pp:325-330
Publication Date(Web):19 October 2008
DOI:10.1016/j.talanta.2008.06.032
An ionic liquid modified carbon paste electrode (IL/CPE) had been fabricated by using hydrophilic ionic liquid 1-amyl-3-methylimidazolium bromide ([AMIM]Br) as a modifier. The IL/CPE was characterized by scanning electron microscope and voltammetry. Electrochemical behavior of rutin at the IL/CPE had been investigated in pH 3.29 Britton–Robinson (B–R) buffer solution by cyclic voltammetry (CV) and square wave voltammetry (SWV). The experimental results suggested that the modified electrode exhibited an electrocatalytic activity toward the redox of rutin. The electron transfer coefficient (α) and the standard rate constant (ks) of rutin at the modified electrode were calculated. Under the selected conditions, the reduction peak current was linearly dependent on the concentration of rutin in the range of 4.0 × 10−8 to 1.0 × 10−5 mol L−1 (r = 0.9998), with a detection limit of 1.0 × 10−8 mol L−1 (S/N = 3). The relative standard deviation (R.S.D.) for six times successful determination of 8.0 × 10−7 mol L−1 rutin was 1.2%. The proposed method was applied to determine rutin in tablet and urine sample. In addition, the IL/CPE exhibited a distinct advantage of simple preparation, surface renewal, good reproducibility and good stability.
Co-reporter:XiaoHui Zheng;XinFeng Zhao;Rong Yang;ShiXiang Wang
Science Bulletin 2008 Volume 53( Issue 6) pp:842-847
Publication Date(Web):2008 March
DOI:10.1007/s11434-007-0510-8
β2-Adrenoceptor (β2-AR) was purified from the rabbit lung tissue by sepharose-salbutamol affinity chromatographic column. To prepare the β2-AR stationary phase, β2-AR was evenly immobilized on the surface of macro-pore silica with a mild chemical coupling method through covalent bond. The retention properties of β2-AR stationary phase were characterized by four ligands, salbutamol sulfate, noradrenaline bitartrate, adrenaline hydrochloride and propranolol hydrochloride, to establish the β2-AR affinity chromatography. Then, the method was used to screen the active compounds from the total extracts of Semen Armeniacae Amarum. The results showed that β2-AR on the surface of the stationary phase could keep its original bioactivity and selectivity. Amygdalin retained in the chromatographic column was proved to be the active compound of the total extracts of Semen Armeniacae Amarum. Compared with the existing chromatographic screening approaches, this method showed a good stability and high selectivity. The active compounds which could interact with β2-AR in traditional Chinese medicine (TCM) could be screened efficiently by this method, providing a new way to screen the active compounds in complicated samples such as TCM.
Co-reporter:Ya Zhang, Jian Bin Zheng
Electrochimica Acta 2007 Volume 52(Issue 25) pp:7210-7216
Publication Date(Web):September 2007
DOI:10.1016/j.electacta.2007.05.039
Ionic liquid, 1-heptyl-3-methylimidazolium hexafluorophosphate (HMIMPF6), has been used to fabricate two new electrodes, carbon ionic liquid electrode (CILE) and ionic liquid modified carbon paste electrode (IL/CPE), using graphite powder mixed with HMIMPF6 or the mixture of HMIMPF6/paraffin liquid as the binder, respectively. The electrochemical behaviors of hydroquinone at the CILE, the IL/CPE and the CPE were investigated in phosphate buffer solution. At all these electrodes, hydroquinone showed a pair of redox peaks. The order of the current response and the standard rate constant of hydroquinone at these electrodes were as follows: CILE > IL/CPE > CPE, while the peak-to-peak potential separation was in an opposite sequence: CILE < IL/CPE < CPE. The results show the superiority of CILE to IL/CPE and CPE, and IL/CPE to CPE in terms of promoting electron transfer, improving reversibility and enhancing sensitivity. The CILE was chosen as working electrode to determine hydroquinone by differential pulse voltammetry, which can be used for sensitive, simple and rapid determination of hydroquinone in medicated skin cosmetic cream.
Co-reporter:Jianbin Zheng, Qinglin Sheng, Lei Li, Yu Shen
Journal of Electroanalytical Chemistry 2007 Volume 611(1–2) pp:155-161
Publication Date(Web):15 December 2007
DOI:10.1016/j.jelechem.2007.08.013
A new bismuth hexacyanoferrate (BiHCF) modified carbon ceramic electrodes (CCEs) fabricated by electrodeposition was reported for the first time. The electrochemical behavior of the resulting modified electrodes was investigated by cyclic voltammetry. The BiHCF-modified CCEs presented good electrocatalytic activity toward the oxidation of hydrazine at a reduced overpotential and was used for amperometric detection of hydrazine. The diffusion coefficient (D) of hydrazine in solution and the catalytic rate constant (kcat) were also calculated by chronoamperometric experiments. In addition, the present modified electrode exhibited the advantages of simple preparation, fast response, good stability and reproducibility for hydrazine determination.
Co-reporter:Qinglin Sheng, Hao Yu, Jianbin Zheng
Journal of Electroanalytical Chemistry 2007 Volume 606(Issue 1) pp:39-46
Publication Date(Web):1 August 2007
DOI:10.1016/j.jelechem.2007.04.007
A new kind of modified electrode fabricated by mechanically attaching terbium hexacyanoferrate (TbHCF) samples to the surface of carbon ceramic electrodes (CCEs) derived from sol–gel technique was proposed. The resulting modified electrodes exhibit well-defined redox responses with the formal potential of +0.225 V (vs. SCE) at a scan rate of 20 mV s−1 in 0.5 M KCl (pH 7) solution. The voltammetric characteristics of the TbHCF-modified CCEs in the presence of different alkali metal cations (Li+, Na+, K+, Rb+ and Cs+) were investigated by voltammetry. The TbHCF-modified CCEs presented a good electrocatalytic activity toward the ascorbic acid (AA) and was used for amperometric detection of AA. The diffusion coefficient (D) of AA in solution and the catalytic rate constant (kcat) were also calculated by chronoamperometry experiment. In addition, the TbHCF-modified CCEs exhibited a distinct advantage of the ability for amperometric detection of AA in the presence of uric acid (UA) by controlling the applied potential at low value (0.25 V).
Co-reporter:Hao Yu, Qing-Lin Sheng, Lei Li, Jian-Bin Zheng
Journal of Electroanalytical Chemistry 2007 Volume 606(Issue 1) pp:55-62
Publication Date(Web):1 August 2007
DOI:10.1016/j.jelechem.2007.04.014
A new method for rapid electrochemical deposition of a compact and thick Prussian blue film on the composite ceramic carbon electrode (CCE) surface from a single ferricyanide solution in the presence of HAuCl4 was investigated by electrochemical and SEM techniques. The nature of the electrode material and experiment conditions such as the effect of pH, concentration of HAuCl4 as well as the initial concentration of ferricyanide were also studied carefully. The results showed that the formation rate of Prussian blue on the CCE surface was dramatically improved with the addition of HAuCl4. Compared to other substrate material, the formation rate of Prussian blue on the CCE surface from a single acid ferricyanide solution in the presence of HAuCl4 was higher due to the porosity of the sol–gel material and the surface roughness. Furthermore, this Prussian blue modified electrode showed high stability and excellent electrocatalytic activity to hydrogen peroxide. The present method was convenient and rapid for the preparation of a compact and thick Prussian blue film compared to other method reported previously.
Co-reporter:Ya ZHANG;Jian-Bin ZHENG
Chinese Journal of Chemistry 2007 Volume 25(Issue 11) pp:1652-1657
Publication Date(Web):13 NOV 2007
DOI:10.1002/cjoc.200790305
An ionic liquid bulk-modified carbon paste electrode (M-CPE) has been fabricated by using 1-heptyl-3-methylimidazolium bromide as a modifier. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to evaluate the electrocatalytic activity of the proposed electrode by choosing p-aminophenol (p-AP) as a model compound. Both at a bare carbon paste electrode (CPE) and the M-CPE, p-AP yielded a pair of redox peaks in 0.1 mol·L−1 phosphate buffer solution (PBS, pH 7.0). At the CPE, the peak-to-peak potential separation (ΔEp) was 0.233 V, while at the M-CPE the ΔEp was decreased to 0.105 V. Furthermore, the current response to p-AP at the M-CPE was 10.2 times of that at the CPE by DPV. The electron transfer rate constant (ks) of p-AP at the M-CPE was 13.3 times of that at the CPE. Under the optimal condition, a linear dependence of the catalytic current versus p-AP concentration was obtained in the range of 2.0×10−6 to 3.0×10−4 mol·L−1 with a detection limit of 6.0×10−7 mol·L−1 by DPV. In addition, compared to other modified method the proposed electrode exhibited distinct advantages of simple prapartion, surface renewal, good reproducibility and good stability. It has been used to determine p-AP in simulated wastewater samples.
Co-reporter:Hao Yu;Jian-Bin Zheng
Chinese Journal of Chemistry 2007 Volume 25(Issue 4) pp:
Publication Date(Web):5 APR 2007
DOI:10.1002/cjoc.200790094
A copper hexacyanoferrate modified ceramic carbon electrode (CuHCF/CCE) had been prepared by two-step sol-gel technique and characterized using electrochemical methods. The resulting modified electrode showed a pair of well-defined surface waves in the potential range of 0.40 to 1.0 V with the formal potential of 0.682 V (vs. SCE) in 0.050 mol·dm−3 HOAc-NaOAc buffer containing 0.30 mol·dm−3 KCl. The charge transfer coefficient (α) and charge transfer rate constant (ks) for the modified electrode were calculated. The electrocatalytic activity of this modified electrode to hydrazine was also investigated, and chronoamperometry was exploited to conveniently determine the diffusion coefficient (D) of hydrazine in solution and the catalytic rate constant (kcat). Finally, hydrazine was determined with amperometry using the resulting modified electrode. The calibration plot for hydrazine determination was linear in 3.0×10−6–7.5×10−4 mol·dm−3 with the detection limit of 8.0×10−7 mol·dm−3. This modified electrode had some advantages over the modified film electrodes constructed by the conventional methods, such as renewable surface, good long-term stability, excellent catalytic activity and short response time to hydrazine.
Co-reporter:Jianbin Zheng, Ya Zhang, Pingping Yang
Talanta 2007 Volume 73(Issue 5) pp:920-925
Publication Date(Web):31 October 2007
DOI:10.1016/j.talanta.2007.05.016
An ionic liquid-type carbon paste electrode (IL-CPE) had been fabricated by replacing non-conductive organic binders with a conductive room temperature ionic liquid, 1-pentyl-3-methylimidazolium hexafluorophosphate (PMIMPF6). The electrochemical responses of calcium dobesilate were investigated at the IL-CPE and the traditional carbon paste electrode (T-CPE) in 0.05 mol L−1 H2SO4, respectively. The results showed the superiority of IL-CPE to T-CPE in terms of provision of higher sensitivity, faster electron transfer and better reversibility. A novel method for determination of calcium dobesilate was proposed. The oxidation peak current was rectilinear with calcium dobesilate concentration in the range of 8.0 × 10−7 to 1.0 × 10−4 mol L−1, with a detection limit of 4.0 × 10−7 mol L−1 (S/N = 3) by differential pulse voltammetry. The proposed method was applied to directly determine calcium dobesilate in capsule and urine samples.
Co-reporter:Hongfang Zhang, Lifeng Xu, Jianbin Zheng
Talanta 2007 Volume 71(Issue 1) pp:19-24
Publication Date(Web):15 January 2007
DOI:10.1016/j.talanta.2006.03.017
The anodic voltammetric behavior of resveratrol was studied using cyclic and square wave voltammetric techniques. The oxidation of resveratrol is irreversible and exhibits an adsorption controlled process which is of pH dependence. The oxidation mechanism was proposed in this work. The dependence of the current on pH, the concentration and nature of buffer, and scan rate was investigated to optimize the experimental conditions for the determination of resveratrol. It was found that the optimum buffer for the determination of resveratrol is 1.0 × 10−3 M KCl + 0.1 M HNO3 solution with the pH of 1.0. In the range of 5.00 × 10−9 to 1.65 × 10−7 M, the current measured by square wave voltammetry presents a good linear property as a function of the concentration of resveratrol. In addition, the reproducibility, precision and accuracy of the method were checked as well. The method was applied for the determination of resveratrol in Chinese patent medicine and diluted urine.
Co-reporter:Jian-bin Zheng;Xiao-xing Liu;Yuan-zhen Zhou;Zhi-rong Suo
Chromatographia 2007 Volume 65( Issue 11-12) pp:707-712
Publication Date(Web):2007 June
DOI:10.1365/s10337-007-0218-6
A simple, sensitive and accurate method for the simultaneous separation and determination of apigenin and four phenolic acids including chlorogenic acid, caffeic acid, p-coumaric acid and ferulic acid in four dried flowers by high performance liquid chromatography with electrochemical detection (ECD) and diode array detection (DAD) has been established. The detection limits of caffeic acid, p-coumaric acid and ferulic acid obtained with ECD were 3, 1 and 4 ng mL−1, and LOD of apigenin and chlorogenic acid obtained with DAD were 1 × 10−2 and 6 × 10−2 μg mL−1. The detection and quantification limits of three phenolic compounds obtained with ECD were two to ninefold greater than those obtained with DAD. As electrochemically inactive compounds, apigenin and chlorogenic acid were detected by DAD. All calibration curves showed good linearity (r ≥ 0.9992) within the test ranges. The recoveries ranged from 95.3 to 101.4% (RSD ≤ 2.9%). This approach could provide scientific evidence for comprehensive evaluation about the effect of the medicine and ensure nutrient status of dried flowers.
Co-reporter:Jian-Bin Zheng;Zu-Chao Meng;Bo Liu;Hong-Fang Zhang
Chinese Journal of Chemistry 2006 Volume 24(Issue 4) pp:
Publication Date(Web):5 APR 2006
DOI:10.1002/cjoc.200690105
The voltammetric behavior of camptothecin (CPT) in Britton-Robinson (B-R) buffer solutions (pH 2.09–9.07) was studied by the means of linear sweep voltammetry (LSV), cyclic voltammetry (CV) and normal pulse voltammetry (NPV) at a hanging mercury drop electrode. In different pH range of B-R buffer solutions, CPT could cause three reduction waves. In B-R buffer solutions (pH 2.09–5.46), wave P1 yielded by CPT was a two-electron wave. Between pH 6.01 and 9.07, CPT could yield two reduction waves P2 and P3. In addition, the pure CPT obtained from camptotheca acumina grown only in China was determined by NPV, and a linear response was observed in the range of 2.0×10−3–4.0×10−2 mmol·L−1 with a 0.9991 correlation coefficient and a 8.0×10−4 mmol·L−1 detection limit for CPT.
Co-reporter:Zheng Jian-Bin;Zhang Hong-Fang;Gao Hong
Chinese Journal of Chemistry 2005 Volume 23(Issue 8) pp:
Publication Date(Web):10 OCT 2005
DOI:10.1002/cjoc.200591042
The electrochemical behavior of chrysin in pH 2.0-9.0 Britton-Robinson (B-R) buffer solutions was studied by the means of linear sweep voltammetry and cyclic voltammetry at a static mercury drop electrode. In different pH range of B-R buffer solutions, chrysin could cause four reduction waves. In pH 2.0-5.8 B-R buffer solutions, wave P1 yielded by chrysin is a one-electron reduction wave, and wave P1′ caused by further reduction of the products of wave P1 in pH<3.0 B-R buffer solution is also a one-electron reduction wave. But in 3.0<pH<5.8 B-R buffer solution wave P1′ was overlapped by the hydrogen wave. Between pH 5.8 and 9.0, chrysin could yield two reduction waves P2 and P3. The former is an irreversible adsorptive wave of ionized chrysin involving one electron and the latter is also an irreversible adsorptive wave of reduction intermediate radical of chrysin involving one electron and one proton. And a linear relationship between ip3 and the concentration of chrysin can be established from 1.0× 10-6 to 4.0×10-5 mol·L-1 (r=0.9924) with the detection limit of 5×10-7 mol·L-1. In addition, the antioxidant ability of chrysin was investigated by linear sweep voltammetry (LSV). The determination result of IC50 of chrysin showed that chrysin is a good antioxidant.
Co-reporter:Zun-Ting Zhang;She-Ying Dong;Jian-Bin Zheng;Hong-Fang Zhang;Hong Gao
Chinese Journal of Chemistry 2004 Volume 22(Issue 9) pp:
Publication Date(Web):26 AUG 2010
DOI:10.1002/cjoc.20040220909
Voltammetric behavior of sodium 7-methoxyl-4′-hydroxylisoflavone-3′-sulfonate (SMHS) in the aqueous solution from pH 1 to 5 was studied by linear sweep voltammetry, cyclic voltammetry and normal pulse voltammetry. Experimental results showed that in 0.2 mol*L−1 sodium citrate-hydrochloric acid buffer solution (pH=4.65), SMHS caused only one reduction wave at −1.34 V (vs. saturated calomel electrode, SCE), which was an h-reversible adsorptive wave of SMHS protonized involving one electron and one proton. The peak current of SMHS on linear sweep voltammogram was proportional to its concentration in the range of 8.0 × 10 −8.0·10 mol*L−1 (r = 0.995). and the detection limit was 5.0·10−-6mol*L−1. The method was applied to determination of SMHS, in synthetic samples. In addition, its scavenging effect on superoxide anion radical was studied by the auto-oxidation of pyrogallol in HCI-tris buffer solution (pH = 8.2) in order to explain its peculiar biological effects. The experimental results proved that SMHS has antioxidant quality, and it is an efficient free radical scavenger of superoxide anion radical.
Co-reporter:Sheying Dong, Jianbin Zheng, Hong Gao
Analytical Biochemistry 2003 Volume 323(Issue 2) pp:151-155
Publication Date(Web):15 December 2003
DOI:10.1016/j.ab.2003.08.022
Voltammetric behavior of 4′,7-dimethoxy-3′-isoflavone sulfonic sodium (DISS) was studied by linear sweep voltammetry and cyclic voltammetry. DISS caused two waves between pH 8.0 and 12.0. Above pH 8.0, the peak current of first wave Pc1 of DISS was enhanced in the presence of cetyltrimethylammonium bromide (CTAB). Based on this, a novel method for the determination of DISS was proposed. In Britton–Robinson buffer solution (pH 11.7) containing 9.4 × 10−6 mol L−1 CTAB, the peak potential of first wave Pc1 of DISS was −1.59 V (vs standard saturated calomel electrode) and its first-order derivative peak current was proportional to the concentration of DISS in the range 5.0 × 10−8–6.0 × 10−7 mol L−1 (r=0.998). The detection limit was 1 × 10−8 mol L−1, which was 10 times lower than that of the corresponding reduction wave. The method was applied to the determination of DISS in synthetic samples.
Co-reporter:Xiu-Qi Zhang;Jian-Bin Zheng;Hong Gao
Chinese Journal of Chemistry 2001 Volume 19(Issue 10) pp:
Publication Date(Web):26 AUG 2010
DOI:10.1002/cjoc.20010191003
Fourier self-deconvolution was the most effective technique in resolving overlapping bands, in which deconvolution function results in deconvolution and apodization smoothes the magnified noise. Yet, the choice of the original half-width of each component and breaking point for truncation is often very subjective. In this paper, the method of combined wavelet transform with curve fitting was described with the advantages of an enhancement of signal to noise ratio as well as the improved fitting condition, and was applied to objective optimization of the original half-widths of components in unresolved bands for Fourier self-deconvolution. Again, a noise was separated from a noisy signal by wavelet transform, therefore, the breaking point of apodization function can be determined directly in frequency domain. Accordingly, some artifacts in Fourier self-deconvolution were minimized significantly.
Co-reporter:Hongbo Zhong, Jun Zhang, Min Gao, Jianbin Zheng, Guanbin Li, Liren Chen
Chemometrics and Intelligent Laboratory Systems 2001 Volume 59(1–2) pp:67-74
Publication Date(Web):28 November 2001
DOI:10.1016/S0169-7439(01)00145-9
The structure and algorithm of the discrete wavelet neural network (DWNN) are described. The network is constructed by the error back propagation neural network using Morlet mother wavelet basic function as node activation function. The effect of wavelet base number, learning rate factor and momentum factor on prediction are discussed. The experimental results of the quantitative computation for the concentration of mono-component and multi-component in oscillographic chronopotentiometric determination (OCPD) show that number of epochs is less than 1000, the recovery is between 94.37% and 104.3%. Compared with standard back propagation neural network, DWNN has higher convergence rate and prediction accuracy.
Co-reporter:Yan Li, Xiao-Rong Liu, Xiao-Hui Ning, Can-Can Huang, ... Jun-Cai Zhang
Journal of Pharmaceutical Analysis (November 2011) Volume 1(Issue 4) pp:258-263
Publication Date(Web):1 November 2011
DOI:10.1016/j.jpha.2011.09.001
An electrochemical sensor incorporating a signal enhancement for the determination of lead (II) ions (Pb2+) was designed on the basis of the thrombin-binding aptamer (TBA) as a molecular recognition element and ionic liquid supported cerium oxide (CeO2) nanoparticles–carbon nanotubes composite modification. The composite comprises nanoparticles CeO2, multi-wall carbon nanotubes (MWNTs) and hydrophobic room temperature ionic liquid (RTIL) 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4). The electrochemical sensors were fabricated by immersing the CeO2–MWNTs–EMIMBF4 modified glassy carbon electrode (GCE) into the solution of TBA probe. In the presence of Pb2+, the TBA probe could form stable G-quartet structure by the specific binding interactions between Pb2+ and TBA. The TBA-bound Pb2+ can be electrochemically reduced, which provides a readout signal for quantitative detection of Pb2+. The reduction peak current is linearly related to the concentration of Pb2+ from 1.0×10–8 M to 1.0×10–5 M with a detection limit of 5×10–9 M. This work demonstrates that the CeO2–MWNTs–EMIMBF4 nanocomposite modified GCE provides a promising platform for immobilizing the TBA probe and enhancing the sensitivity of the DNA-based sensors.
Co-reporter:Ai-Li Sun, Gai-Rong Chen, Qing-Lin Sheng, Jian-Bin Zheng
Biochemical Engineering Journal (15 November 2011) Volume 57() pp:1-6
Publication Date(Web):15 November 2011
DOI:10.1016/j.bej.2011.06.008
A sensitive label-free electrochemical immunosensing platform was designed by a redox matrix of gold nanoparticles (GNPs), Azure І and multi-wall carbon nanotubes (MWCNT) self-assemblying nanocomposite. To construct the immunosensor, MWCNT was first dispersed in Nafion (Nf) to obtain a homogeneous solution and then it was dropped on the surface of the gold electrode (Au). Then the positively-charged redox molecule, Azure І, was entrapped into MWCNT–Nf film to form a redox nanostructural membrane. Next, the negatively charged gold nanoparticles (GNPs) were assembled to the interface through the electrostatic force. Finally, carcinoembryonic antibody molecules could be absorbed into the GNPs/Azure І/MWCNT–Nf immobilization matrix. Using carcinoembryonic antigen (CEA) as a model protein, the electrochemical immunosensor exhibited good stability and reproducibility, as well as good selectivity and storage stability. This strategy presented a promising platform for sensitive and facile monitoring of CEA.Highlights► In this work we construct the GNPs/Azure І/MWCNT–Nf matrix for the CEA antibody immobilization. ► The GNPs/Azure І/MWCNT–Nf matrix provides porous nanostructure, good electrochemical redox reversibility and biocompatibility. ► Based on the direct immunoassay format, the label-free immunosenors achieve a broader linear range, high sensitivity and good stability.
Co-reporter:
Analytical Methods (2009-Present) 2015 - vol. 7(Issue 19) pp:NaN8372-8372
Publication Date(Web):2015/08/26
DOI:10.1039/C5AY01710F
A new sandwich structure nanocomposite of Pt nanoparticles supported on PANI modified graphene was synthesized and used for fabricating a nitrite sensor. The morphology and composition of the nanocomposites were characterized using transmission electron microscopy and X-ray diffraction. Electrochemical investigations indicated that the nanocomposites possess an excellent electrochemical oxidation ability towards nitrites. The sensor exhibited two linear ranges: one from 0.4 μM to 0.99 mM with a correlation coefficient of 0.9974 and a sensitivity of 485.5 μA mM−1 cm−2; and another from 0.99 mM to 7.01 mM with a correlation coefficient of 0.9981 and a sensitivity of 154.3 μA mM−1 cm−2. The limit of detection (LOD) of this sensing system was 0.13 μM at a signal-to-noise ratio of 3. Additionally, the sensor exhibited good reproducibility, long-term stability, and anti-interference performance.
Co-reporter:
Analytical Methods (2009-Present) 2015 - vol. 7(Issue 12) pp:NaN4987-4987
Publication Date(Web):2015/04/30
DOI:10.1039/C5AY00646E
The conformational changes of myoglobin (Mb) during urea-induced protein unfolding were investigated using an electrochemical method. Using several different concentrations of urea, Mb adsorbed onto a montmorillonite clay modified glassy carbon electrode (GCE) was denatured. It was determined from the relative differences in the percentage of Mb unfolding that urea-induced Mb unfolding is a one-step, two-state transition process. The results obtained using electrochemical analysis were in agreement with those obtained by UV-vis spectroscopy and fluorescence spectroscopy, confirming our observations. Thermodynamic parameters during the conformational changes were also calculated to further characterize the unfolding process of Mb. Furthermore, two typical denaturants, urea and acid, were synergistically utilized to maintain GCE incorporated Mb in its most unfolded state, while simultaneously maintaining the presence of heme groups. Under optimal conditions, the unfolded Mb/clay/GCE exhibited accelerated direct electron transfer relative to the native Mb/clay/GCE. Additionally, the sensitivity for the detection of H2O2 was increased nearly 10-fold, and the limit of detection (LOD) for H2O2 was reduced to 0.3 μM for the unfolded Mb/clay/GCE relative to the native Mb/clay/GCE. The present work introduces a simple and effective way to study the unfolding of metalloproteins and holds great promise for the design of novel sensitive biosensors.
Co-reporter:Jianbin Zheng, Yaping He, Qinglin Sheng and Hongfang Zhang
Journal of Materials Chemistry A 2011 - vol. 21(Issue 34) pp:NaN12879-12879
Publication Date(Web):2011/07/26
DOI:10.1039/C1JM11707F
Taking advantages of the striking properties of both self-assembly and biocatalysis, a highly sensitive glucose electrochemical biosensor was proposed by using DNA–GE as biocatalysis target-guide to deposit Au nanoparticles (AuNPs). AuNPs interacted with thiol and amino groups of DNA strands, which make the reaction much easier and faster. Furthermore, the proposed AuNPs/glucose oxidase (GOx)/DNA–GE/glassy carbon (GC) modified electrode achieved the direct electrochemistry and electrocatalysis of GOx. The growth of AuNPs was confirmed by scanning electron microscopy and electrochemical methods. The characterizations of the electrode modified after each assembly step and the content of AuNPs on the electrode surfaces during the growth process were investigated by cyclic voltammetry. The amount of AuNPs was relative to the amount of glucose oxidized accompanying with the biocatalytic process of GOx. The biosensor showed a linearity with glucose concentration in the range of 0.8–50 μM with a detection limit of 0.3 μM (S/N = 3). The sensitivity was 2.4 × 104 μA mM−1. The combination of self-assembly and biocatalysis offers the new design of enzymatic biosensors with potential applications in direct electrochemistry and biocatalysis.
Co-reporter:Qinglin Sheng, Ni Cheng, Wushuang Bai and Jianbin Zheng
Chemical Communications 2015 - vol. 51(Issue 11) pp:NaN2117-2117
Publication Date(Web):2014/12/03
DOI:10.1039/C4CC08954E
An ultrasensitive cytosensor based on DNA-rolling-circle-amplification-directed enzyme-catalyzed polymerization is demonstrated. As a proof of concept, the cytosensor shows excellent sensitivity for MCF-7 cell detection with a lower detection limit of 12 cells per mL.
Co-reporter:
Analytical Methods (2009-Present) 2014 - vol. 6(Issue 21) pp:
Publication Date(Web):
DOI:10.1039/C4AY01702A
In this work, a nonenzymatic reduced glutathione (GSH) sensor was constructed based on the electrodepoition of Ni–Al layered double hydroxides (Ni–Al LDHs) on multiwall carbon nanotubes (MWCNTs) modified glassy carbon electrode (GCE). The morphologies and compositions of Ni–Al LDHs/MWCNTs nanocomposite were investigated by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Cyclic voltammetry and amperometry were employed to explore the electrochemical properties and performance of Ni–Al LDHs/MWCNTs nanocomposites in sensing and detection. The results indicated that the response current of GSH oxidation at the Ni–Al LDHs/MWCNTs/GCE was obviously higher than that at the MWCNTs/GCE or the Ni–Al LDHs/GCE. The amperometric current of the sensor is proportional to the concentration of GSH in a linear range of 1.2 to 1630.0 μM with a detection limit of 0.7 μM at a signal-to-noise ratio of 3. In addition, the sensor exhibits easy preparation, low cost, good stability and anti-interference.
Co-reporter:
Analytical Methods (2009-Present) 2015 - vol. 7(Issue 16) pp:NaN6903-6903
Publication Date(Web):2015/07/17
DOI:10.1039/C5AY01329A
A facile and effective electrochemical sensing technique was developed by the electrodeposition of Prussian blue on polyaniline (PANI) coated halloysite nanotubes (HNTs). Owing to the special structure of the PB-PANI-HNT nanocomposite, the sensor possessed excellent electrocatalytic ability towards H2O2 reduction. The amperometric study demonstrated that the H2O2 sensor exhibits good performance with a linearity in the range from 4 μM to 1064 μM. The limit of detection (LOD) was 0.226 μM (S/N = 3) and the sensitivity was calculated to be 0.98 μA (μM−1 cm−2). Moreover, the interference from the common interfering species such as glucose, ascorbic acid, dopamine and uric acid can be effectively avoided, and the sensors exhibit long-term stability, thus holding promise for the development of amperometric biosensors.
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