Co-reporter:Shuqing Dong, Qing Bi, Chengdong Qiao, Yaming Sun, Xia Zhang, Xiaoquan Lu, Liang Zhao
Talanta 2017 Volume 173(Volume 173) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.talanta.2017.05.045
•GCE modified with β-CDs-GQDs composites was prepared successfully.•The β-CDs-GQDs/GCE demonstrated well-marked peak current difference to tyrosine enantiomers by CV and DPV.•The electrochemical chiral sensor showed good selectivity and low detection limit to Tyr enantiomers.•The electrochemical chiral tyrosine sensor obtained the satisfied results on the detection of L-Tyr in blood serum samples.An electrochemical sensor using the composites of graphene quantum dots (GQDs) and β-cyclodextrins (β-CDs) functionalized glassy carbon electrode (GCE) was developed for determination and recognition of tyrosine (Tyr) enantiomers which are biomarker of depression. The modified electrode is simple to fabricate and rapid, sensitive, selective to detect the Tyr enantiomers. In order to further validate the feasibility of the electrochemical sensor in real samples, the sensor was applied to the detection of L-Tyr in blood serum samples of healthy people and depression patients, and found that the quantities of L-Tyr of depression patients in serum is less than healthy people. The β-CDs-GQDs composites were fabricated as modification layer of electrodes. GQDs were used as substrate and functionalized with β-CDs. The β-CDs-GQDs composites utilized nanosize of GQDs and enantioselectivity of β-CDs to realize chiral recognition of Tyr. The β-CDs-GQDs modified electrode presented significant difference in the oxidation peak current with ratio of L to D-Tyr reaching 2.35. The detection limits of L-Tyr and D-Tyr were 6.07×10−9 M and 1.03×10−7 M, respectively and superior to detection limits of the reported methods. In addition, the stability and reproducibility of the prepared modified electrode were investigated, and achieved good results.Download high-res image (155KB)Download full-size image
Co-reporter:Xinhe Liu, Xiuhui Liu, Hongwei Wei, Guangjie Song, Huixia Guo, Xiaoquan Lu
Sensors and Actuators B: Chemical 2017 Volume 252(Volume 252) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.snb.2017.06.027
•Small-sized AgNPs uniformly deposited SDS functionalized carbon nanotube.•Fabricated a novel non-enzymatic O2− sensor based on AgNPs/SDS-MWCNTs/GCE.•A remarkable low detection limit of 8.97 × 10−11 M was achieved.•The sensor can measure the release of O2− from living cells directly, and is AA dose-dependent manner.Considering the crucial roles of superoxide anion (O2−) in pathological conditions, it is of great urgency to establish a reliable approach for real-time determination of O2−. Herein, a sensitive non-enzymatic sensor was constructed based on silver nanoparticles (AgNPs) and sodium dodecyl sulfate functionalized carbon nanotubes (SDS-MWCNTs) composites to measure the release of O2− from living cells. As an analytical and sensing platform, the AgNPs/SDS-MWCNTs modified glassy carbon electrode exhibited excellent electrochemical performance toward O2− with a determination limit as low as 0.0897 nM and wide linear range of 6 orders of magnitude, which was superior to other O2− electrochemical sensors. The excellent performance was attributed to the SDS-MWCNTs composites being used as effective load matrix for the deposition of AgNPs. Importantly, this novel non-enzymatic sensor could be applied to determination of O2− released from living cells, and the amount of flux of O2− increased accordingly with the improving of the concentration of AA, which has the possibility of application in clinical diagnostics to assess oxidative stress of living cells.Download high-res image (113KB)Download full-size image
Co-reporter:Zhihua Wang, Yaxuan Qian, Xiaolong Wei, Yafang Zhang, Guofan Wu, Xiaoquan Lu
Electrochimica Acta 2017 Volume 250(Volume 250) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.electacta.2017.08.076
A novel of eco-friendly molecularly imprinted electrochemical luminescence biosensor was designed, based on nanomaterials, CdSeTe/ZnS core-shell QDs and molecularly imprinted polymer composites modified glass carbon electrode. Combining the superior selectivity of molecularly imprinted polymer and the high sensitivity of electrochemical luminescence would achieve the trace determination of dopamine. And the cavities in molecularly imprinted polymer after eluting were applied as the substrate to capture target molecular dopamine. The electron transform channel for the redox reaction of CdSeTe/ZnS QDs and co-reaction K2S2O8 was blocked with the increase of dopamine concentration, resulting in the cathodic ECL intensity decreased correspondingly. Therefore, the dopamine was detected in the concentration range from 1 × 10−14 mol/L to 2.5 × 10−12 mol/L, with the low detection limit of 3.3 × 10−15 mol/L. The MIP-ECL biosensor showed easy preparation, low lost, lower detection limit, good selectivity and stability, and could be used for the detection of dopamine in the human serum successfully.
Co-reporter:Yuelin Liu, Xiuhui Liu, Yidan Liu, Guoan Liu, Lan Ding, Xiaoquan Lu
Biosensors and Bioelectronics 2017 Volume 90(Volume 90) pp:
Publication Date(Web):15 April 2017
DOI:10.1016/j.bios.2016.11.015
•Cys-MWCNTs were used as effective matrix, loading on great amount of AgNps.•A novel non-enzymatic O2•− sensor was fabricated based on AgNPs/Cys-MWCNTs/GCE•The O2•− sensor exhibited a super low detection limit of 2.33×10-11 M.•It was used to measure the release of O2•− from living cells directly.A novel non-enzymatic superoxide anion (O2•−) sensor was fabricated based on Ag nanoparticles (NPs)/L-cysteine functioned carbon nanotubes (Cys-MWCNTs) nanocomposites and used to measure the release of O2•− from living cells. In this strategy, AgNPs could be uniformly electrodeposited on the MWCNTs surface with average diameter of about 20 nm as exhibited by scanning electronmicroscopy (SEM). Electrochemical study demonstrated that the AgNPs/Cys-MWCNTs modified glassy carbon electrode exhibited excellent catalytic activity toward the reduction of O2•− with a super wide linear range from 7.00×10–11 to 7.41×10-5 M and a low detection limit (LOD) of 2.33×10-11M (S/N=3). Meanwhile, the mechanism for O2•− reduction was also proposed for the first time. Importantly, this novel non-enzymatic O2•− sensor can detect O2•− release from cancer cells under both the external stimulation and the normal condition, which has the great potential application in clinical diagnostics to assess oxidative stress of living cells.This article constructed a novel non-enzymatic sensor for the determination of O2•− by utilizing Cys functionalized MWCNTs as the matrix for electrodepositing of AgNPs. Due to the outstanding electric conductivity of Cys-MWCNTs nanocomposites and the excellent selective catalysis of Ag nanoparticles, this sensor could detect O2•− release from cancer cells under both the external stimulation and the normal condition.Download high-res image (202KB)Download full-size image
Co-reporter:Zhonghua Xue, Xiaofen Wang, Honghong Rao, Xiuhui Liu, Xiaoquan Lu
Analytical Biochemistry 2017 Volume 534(Volume 534) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.ab.2017.07.003
Many strategies have been explored for selectively and sensitively detecting cysteine in different samples. Here, a novel colorimetric sensor based on self-assembly nanostructures of Fe3+-H2O2/Tetramethylbenzidine system with dual-level logic gate function and colorimetric determination of cysteine were firstly explored. The proposed Fe3+-H2O2-TMB system provides a sensitive optical signal due to the selectively reductive ability of cysteine to the oxidized TMB and thus could be successfully applied to the construction of instant on-site visual detection method with a paper based test strip for cysteine determination in a sample solution as well as for a dual-level logic gate fabrication.Download high-res image (178KB)Download full-size image
Co-reporter:Cai-He Wang;Dong-Dong Qin;Duo-Liang Shan;Jing Gu;Yong Yan;Jing Chen;Qiu-Hong Wang;Cai-Hua He;Yang Li;Jing-Jing Quan
Physical Chemistry Chemical Physics 2017 vol. 19(Issue 6) pp:4507-4515
Publication Date(Web):2017/02/08
DOI:10.1039/C6CP08066A
Graphitic carbon nitride (g-C3N4) has been widely studied as a metal-free photocatalyst, leading to some excellent results; however, the rapid recombination of photogenerated charge carriers substantially limits its performance. Here, we establish two types of g-C3N4-based heterojunction (type II and nonmediator assisted Z-scheme) photoanodes on a transparent conducting substrate via coupling with rod-like and nanoparticulate WO3, respectively. In these composites, g-C3N4 film grown by electrophoretic deposition of exfoliated g-C3N4 serves as the host or guest material. The optimized type II WO3/g-C3N4 composite exhibits an enhanced photocurrent of 0.82 mA cm−2 at 1.23 V vs. RHE and an incident photo-to-current conversion efficiency (IPCE) of 33% as compared with pure WO3 nanorods (0.22 mA cm−2 for photocurrent and 15% for IPCE). Relative to pure g-C3N4 film (with a photocurrent of several microampere and an IPCE of 2%), a largely improved photocurrent of 0.22 mA cm−2 and an IPCE of 20% were acquired for the Z-scheme g-C3N4/WO3 composite. The enhancement can be attributed to accelerated charge separation in the heterointerface because of the suitably aligned band gap between WO3 and g-C3N4, as confirmed by optical spectroscopy and ultraviolet photoelectron spectroscopy (UPS) analysis. The photocatalytic process and mechanism of the g-C3N4-based heterojunctions are proposed herein, which potentially explain the origin of the enhanced photoelectrochemical performance. This achievement and the fundamental information supplied here indicate the importance of rationally designing heterojunction photoelectrodes to improve the performance of semiconductors. This is particularly important for materials such as pure g-C3N4 and WO3, as their photoactivities are strongly restricted by high recombination rates.
Co-reporter:Samrat Devaramani;Mahgoub Ibrahim Shinger;Xiaofang Ma;Meng Yao;Shouting Zhang;Dongdong Qin;Xiaoquan Lu
Physical Chemistry Chemical Physics 2017 vol. 19(Issue 28) pp:18232-18242
Publication Date(Web):2017/07/19
DOI:10.1039/C7CP02815F
J- and H-aggregates of zinc tetraphenylporphyrin (ZnTPP) on carbon nanotube films (CNTFs) were prepared using the mixed solvent method. This resulted in completely different structures, such as the four-leaf clover and flower, on the CNTF, which were observed by recording SEM images. Characteristic changes in the electronic spectra of the ZnTPP monomer appeared when it underwent J- and H-aggregation. The measured photocurrent significantly varied for the same molecule when it was aggregated in two different ways on ITO and ITO/CNTF. The electron recombination resistance of the two aggregates, which was investigated using electrochemical impedance spectroscopy, was also different. The photocatalytic efficiency of the J- and H-aggregates was examined by performing methylene blue dye decoloration studies. In addition, a scanning electrochemical microscope was used to investigate the photoinduced charge transfer kinetics of the J- and H-aggregates at the electrode/electrolyte interface as a fresh attempt. The heterogeneous charge transfer constants for the J- and H-aggregates in the presence of light at varied intensities were calculated. Thereby, striking differences in the photophysical, photocatalytic, and photoelectrochemical properties of the J- and H-aggregates were visualized throughout our studies.
Co-reporter:Xiao-yu Yan;Samrat Devaramani;Jing Chen;Duo-liang Shan;Dong-dong Qin;Qin Ma
New Journal of Chemistry (1998-Present) 2017 vol. 41(Issue 6) pp:2436-2442
Publication Date(Web):2017/03/13
DOI:10.1039/C6NJ03887E
Recent research suggests that transition metal phosphides (TMPs) are one of the most promising nobel-metal-free electrocatalysts for catalyzing the hydrogen evolution reaction. In this study, we report rectangular CoP nanosheet (NS) arrays on carbon cloth (CoP NS/CC) via a concise two-step synthetic method. The 3D rectangular CoP NS/CC with a three-dimensional porous and self-supported structure was fabricated via a hydrothermal method, followed by a low-temperature phosphidation treatment. Such 3D rectangular CoP NS/CC, as an HER electrocatalyst in acidic solution, exhibited high activity, good stability, and nearly 100% Faradaic efficiency (FE). The electrocatalyst requires an overpotential of 92, 112 and 195 mV to achieve current densities of 10, 20 and 100 mA cm−2, respectively, and maintain its catalytic stability for more than 50 h. In addition, the electrocatalyst works well in a neutral environment.
Co-reporter:Jing Chen;Qin Ma;Caihe Wang;Xiaoyan Hu;Yunjing Gao;Huan Wang;Dongdong Qin;Xiaoquan Lu
New Journal of Chemistry (1998-Present) 2017 vol. 41(Issue 15) pp:7171-7176
Publication Date(Web):2017/07/24
DOI:10.1039/C7NJ01446E
A novel strategy was developed for the fluorescence detection of nitrite (NO2−) in real samples. The method is based on the reaction of water-dispersible graphite-like carbon nitride (w-g-C3N4) with nitrite (NO2−) in an acidic medium to form a new kind of weak fluorescence species. Under optimal conditions, the limit of detection (LOD) for nitrite (NO2−) detection was determined to be 0.16 nM (S/N = 3), and the relative fluorescence intensity versus logarithm concentration of nitrite (NO2−) showed good linearity in the range from 0 to 58.5 μM with R2 = 0.997. This probe displayed several appealing properties including low-cost, simplicity and convenience, high sensitivity, and excellent selectivity.
Co-reporter:Zhen-Zhen An, Zhuang Li, Yong-Yang Guo, Xiao-Ling Chen, ... Xiao-Quan Lu
Chinese Chemical Letters 2017 Volume 28, Issue 7(Volume 28, Issue 7) pp:
Publication Date(Web):1 July 2017
DOI:10.1016/j.cclet.2017.02.014
In this work, the chitosan and N-doped graphene natively grown on hierarchical porous carbon (N-PC-G/CS) nanocomposite was obtained by ultrasonic method, as a novel sensor platform for determination of tartrazine (TT). The nanocomposite as prepared had well dispersivity in water and excellent conductivity. The N-PC-G/CS nanocomposite was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption-desorption, fourier transform infrared (FTIR) and electrochemical impedance spectroscopy (EIS). The application of N-PC-G/CS for determination of tartrazine (TT) was investigated by chronocoulometry (CC), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under optimized conditions, the sensor displayed a sensitive response to TT within a wide concentration range of 0.05–15.0 μmol/L, the detection limits is 0.036 μmol/L (S/N = 3). Furthermore, this nanocomposite could be efficiently applied for determination of TT in soft drink samples.Download high-res image (166KB)Download full-size imageChitosan and N-doped graphene natively grown on hierarchical porous carbon (N-PC-G/CS) nanocomposite was obtained by ultrasonic method, as a novel sensor platform for determination of tartrazine (TT).
Co-reporter:Yidan Liu, Xiuhui Liu, Zhipan Guo, Zhongai Hu, Zhonghua Xue, Xiaoquan Lu
Biosensors and Bioelectronics 2017 Volume 87() pp:101-107
Publication Date(Web):15 January 2017
DOI:10.1016/j.bios.2016.08.015
•A new type of supporting material PGN for immobilizing enzyme was explored.•The HRP/PGN/GCE displays excellent electrochemical activity toward the reduction of H2O2.•A significant low detection limit of 0.0267 nM and wider linear range of 7 orders of magnitude were achieved.•The constructed electrode was used for in situ detecting H2O2 release from cells.A viable and simple method for preparing porous graphene network using silver nanoparticles (AgNPs) etching was proposed, and a sensitive biosensor was constructed based on the porous graphene (PGN) and horseradish peroxidase (HRP) to measure the release of H2O2 from living cells. Owing to the large surface area and versatile porous structure, the use of nanoporous materials can significantly improve the analysis performance of the biosensor by loading large amounts of enzyme and accelerating diffusion rate. Meanwhile, the constructed electrode exhibited excellent electrochemical performance toward H2O2 with a determination limit as low as 0.0267 nM and wide linear range of 7 orders of magnitude, which was superior to other H2O2 electrochemical sensors. Thus, this novel biosensor can detect the H2O2 release from living cells not only under normal physiological conditions (10−8–10−7 M) but also in emergency state with the increased concentration (~10−4 M). This work provides tremendous potential for real-time tracking of the secretion of H2O2 in different types of physiological and pathological investigations.A novel biosensor is constructed based on the porous graphene (PGN) and horseradish peroxidase (HRP). Due to the unique porous structure of PGN and the excellent selective catalysis of HRP, this biosensor shows superior sensitivity toward detecting the release of H2O2 from living cells.
Co-reporter:Tao Liu, Xiaoyu Yan, Pinxian Xi, Jing Chen, ... Xiaoquan Lu
International Journal of Hydrogen Energy 2017 Volume 42, Issue 20(Volume 42, Issue 20) pp:
Publication Date(Web):18 May 2017
DOI:10.1016/j.ijhydene.2017.04.116
•We followed two-step strategy to grow NiCoP nanowires on the Ni foam (NF).•Ni doped composite materials exhibited the higher activity.•The NiCoP NWs for HER exhibited excellent, stability and electron transfer rate.The design and synthesis of highly active hydrogen evolution reaction (HER) catalyst with strong stability is highly desirable and challenging. In this work, we followed simple two-step strategy to grow Nickel–Cobalt phosphide nanowires (NiCoP NWs) directly on the Ni foam (NF) by hydrothermal method. Catalytic current density of 10 mA cm−2 at an overpotential of 118 mV has been obtained. Prepared material exhibited long-term stability and nearly 100% Faradaic efficiency in 0.5 M H2SO4 for HER. Ni and Co composite materials with amorphous structure are considered as better catalysts by exhibiting the higher activity. The results in this paper might promote further development of the advanced catalysts for special electrochemical properties and other devices.Download high-res image (329KB)Download full-size image
Co-reporter:Dong-Dong Qin;Qiu-Hong Wang;Jing Chen;Cai-Hua He;Yang Li;Cai-He Wang;Jing-Jing Quan;Chun-Lan Tao
Sustainable Energy & Fuels (2017-Present) 2017 vol. 1(Issue 2) pp:248-253
Publication Date(Web):2017/03/29
DOI:10.1039/C6SE00045B
Phosphorus-doped TiO2 nanotube arrays have been prepared via a phosphine annealing protocol and have been found to be efficient towards visible-light-driven water oxidation. Optimal visible light photocurrents of 0.25 mA cm−2 at 1.23 V and 0.85 mA cm−2 at 2.0 V vs. the RHE are achieved, which are the best reported values for phosphorus-doped TiO2.
Co-reporter:Mahgoub Ibrahim Shinger, Ahmed Mahmoud Idris, Samrat Devaramani, Dong-Dong Qin, Hind Baballa, Shou-Ting Zhang, Duo-Liang Shan, Xiaoquan Lu
Journal of Environmental Chemical Engineering 2017 Volume 5, Issue 2(Issue 2) pp:
Publication Date(Web):1 April 2017
DOI:10.1016/j.jece.2017.02.032
•In situ fabrication of graphene-based Ag3PO4@AgBrcomposite.•Simulated sunlight induced the photocatalytic activity of GO-Ag3PO4@AgBr composite.•GO-Ag3PO4@AgBr composite exhibited enhanced photocatalytic activity toward different organic dyes.•The effect of the experimental condition on the catalytic activity of GO-Ag3PO4@AgBr composite.In this study, graphene grafted Ag3PO4@AgBr (GO-Ag3PO4@AgBr) composite with enhanced photocatalytic performance was synthesized via in situ fabrication method. The synthesized composite was characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS) and X-ray photoelectron spectroscopy (XPS). The GO-Ag3PO4@AgBr composite was exhibited higher activity than Ag3PO4@AgBr and bare Ag3PO4. The material characterization and the detailed study of the various parameters which affect the photocatalytic reaction, revealed that the enhanced catalytic activity is related to the surface electric property of the synthesized catalyst. The investigation of the energy band structure further considered as a reason for the enhancement of the multi-electron reaction. Furthermore, the effect of illuminated light on the catalytic performance was also investigated. The results indicated that simulated sunlight significantly affects the catalytic activity compared with visible light. In addition, the photocatalytic experimental conditions were tested, and sonication of the dye/catalyst reaction system for 10 min was selected to be the optimum condition to establish absorption – desorption equilibrium. This work could supply a new way to use natural sunlight to facilitate the practical application of photocatalysts in environment issues.
Co-reporter:Zhonghua Xue, Xiaoxia Fu, Honghong Rao, Mohammed Hassan Ibrahim, Lulu Xiong, Xiuhui Liu, Xiaoquan Lu
Talanta 2017 Volume 174(Volume 174) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.talanta.2017.07.012
•A simple and effective indicator displacement based colorimetric assay for cysteine was explored.•The colorimetric assay can detect cysteine with high selectivity and sensitivity in aqueous solution.•The colorimetric assay can be successfully converted into an INHIBIT logic gate and paper-based analytical device.In this study, we developed an ingenious yet effective strategy for cysteine detection. The colorimetric cysteine assay is established through an indicator displacement process, where Cu2+ and pyrocatechol violet (PV) was employed as receptor and indicator, respectively. Proof-of-concept trials demonstrated that the stronger binding affinity of Cu2+ receptor toward cysteine than PV indicator endowed our colorimetric sensor with high selectivity and excellent sensitivity as well as with a lower detection limit (4.60 μM and 120 µM, S/N =3) by UV–visible spectroscopy and the naked eye as the signal readout, respectively. More importantly, the proposed molecule-exchange process in the indicator displacement process could be successfully used to the fabrication of a colorimetric INHIBIT logic gate and even converted into a facile naked eye analysis through paper-based analytical devices for conveniently and reliably detecting cysteine (CySH) in practical applications.Download high-res image (168KB)Download full-size image
Co-reporter:Zhonghua Xue, Bo Yin, Hui Wang, Mengqian Li, Honghong Rao, Xiuhui Liu, Xinbin Zhou and Xiaoquan Lu
Nanoscale 2016 vol. 8(Issue 10) pp:5488-5496
Publication Date(Web):16 Feb 2016
DOI:10.1039/C6NR00005C
Rapid detection of sarcosine is a key requirement for both diagnosis and treatment of disease. We report here a simple yet sensitive colorimetric nanocomposite platform for rapid detection of sarcosine in alkaline media. The approach exploited the benefits of a rapid color-producing reaction between an organic indicator, 1,2-naphthoquinone-4-sulphonic acid sodium salt (NQS), and the analyte of sarcosine species as well as the good catalytic ability of graphene oxide (GO) to the formation of highly colored products due to its good water dispersibility, extremely large surface area and facile surface modification. As a result, a NQS functionalized GO nanocomposite through π–π stacking has been demonstrated to be useful as a highly efficient catalyst system for the selective and sensitive colorimetric determination of sarcosine by providing a nanocomposite-amplified colorimetric response. Meanwhile, the strategy offered excellent selectivity toward sarcosine species against other amino acids as well as a satisfying detection limit of 0.73 μM. More importantly, by using an electrochemical method, a credible sensing mechanism of GO nanocomposite-based colorimetric platform for a special analyte determination can be easily verified and elucidated, which also provides an attractive alternative to conventional characterization strategies.
Co-reporter:Yanru Fan, Yu Huang, Yuan Jiang, Xingming Ning, Xuemei Wang, Duoliang Shan, Xiaoquan Lu
Journal of Colloid and Interface Science 2016 Volume 462() pp:100-109
Publication Date(Web):15 January 2016
DOI:10.1016/j.jcis.2015.09.063
Three zinc-tetraarylporphyrins were prepared in order to investigate the effects of systematic meso-π-extension on the redox behaviors and interfacial electron transfer kinetics. The meso-π-extension increased at a 2n pattern, where 2n was the benzene ring number in an aryl group and the aryl group represented phenyl, naphthyl and pyrenyl group, respectively. The structures of zinc-tetraarylporphyrins and hydroquinone were optimized by using density functional theory. The bimolecular reactions between zinc-tetraarylporphyrins and hydroquinone at the liquid–liquid interface were studied by using scanning electrochemical microscopy. There was an inverse electron transfer rate-overall driving force dependence by comparison of three bimolecular reactions. It was suggested that the formation of a precursor between zinc-tetraarylporphyrin cation and hydroquinone was deeply influenced by the increasing steric hindrance from phenyl group to pyrenyl group. The electron transfer rate constant depended strongly on the overall driving force for each bimolecular reaction, with transfer coefficients of 0.41, 0.37 and 0.39.
Co-reporter:Jing Chen, Qin Ma, Xiaoyan Hu, Miao Zhang, Dongdong Qin and Xiaoquan Lu
RSC Advances 2016 vol. 6(Issue 46) pp:39652-39656
Publication Date(Web):13 Apr 2016
DOI:10.1039/C6RA05694F
Cancer classification is a key problem for identifying the genomic biomarkers and treating cancerous tumors in clinical research. The gene data in gene expression profiling are potential biomarkers and can be used to classify cancer samples. However, with the high dimensionality of the gene data, the cancer samples are difficult to classify. The identification of the significant genes is critical for the classification. To identify the significant genes, nonnegative matrix factorization (NMF) uses the sparse basis vectors of the gene data to represent gene information. However, the basis vectors with the imposed sparseness lose much of the useful information in the gene data. To more effectively represent the useful information, a method named Monte Carlo-nonnegative matrix factorization (MC-NMF) is proposed by using Monte Carlo technique in this study. The method is used to classify two cancer samples. The results show that the method can effectively estimate the significance of the genes and classify cancer samples with a high accuracy.
Co-reporter:Zhonghua Xue, Mengqian Li, Honghong Rao, Bo Yin, Xibin Zhou, Xiuhui Liu and Xiaoquan Lu
RSC Advances 2016 vol. 6(Issue 25) pp:20520-20520
Publication Date(Web):19 Feb 2016
DOI:10.1039/C6RA90016J
Correction for ‘Phase transformation-controlled synthesis of CuO nanostructures and their application as an improved material in a carbon-based modified electrode’ by Zhonghua Xue et al., RSC Adv., 2016, 6, 12829–12836.
Co-reporter:Zhonghua Xue, Mengqian Li, Honghong Rao, Bo Yin, Xibin Zhou, Xiuhui Liu and Xiaoquan Lu
RSC Advances 2016 vol. 6(Issue 16) pp:12829-12836
Publication Date(Web):25 Jan 2016
DOI:10.1039/C5RA22297D
Column-shaped CuO nanorods have been synthesized by a two-step “precursor formation-crystallization” process using a hydrothermal method with advantages of being template- and surfactant-free. The regular particle morphology of the as-prepared material was explored to be produced through a good transformation process coupled with a series of phase changes from CuCl, to Cu2(OH)3Cl, to Cu(OH)2, which rely on heat by using NaOH and n-butylamine solution in a sealed vessel, and finally to CuO. Scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), X-ray diffraction (XRD), and Raman spectroscopy were employed to characterize the morphology and structures of our samples. The as-prepared CuO nanostructures have been employed to modify a glassy carbon electrode for nonenzymatic glucose oxidation. Compared with the bare glassy carbon electrode, the CuO modified electrode exhibits satisfactory performance with an apparent rate constant of κ as high as 231.0 M−1 s−1 due to its high specific surface area and especially good electron delivery capability of the CuO nanorods.
Co-reporter:Qiao-Ling Ma, Hong Xia, Shou-Ting Zhang, Dong-Dong Qin, Samrat Devaramani, Duo-Liang Shan and Xiao-Quan Lu
RSC Advances 2016 vol. 6(Issue 15) pp:12249-12255
Publication Date(Web):28 Dec 2015
DOI:10.1039/C5RA25114A
A simple amine embellished tube array was assembled at the liquid–liquid interface to study ion transfer behavior. Variation in the pH of the solution resulted in three different protonation states at the amino groups of the nanochannel, which in turn regulated ion transport, similar to the switching effect of ion channels in vivo.
Co-reporter:Juanjuan Lu, Xiuhui Liu, Yanjun Zhang, Yidan Liu, Ming Li and Xiaoquan Lu
Analytical Methods 2016 vol. 8(Issue 4) pp:816-823
Publication Date(Web):11 Dec 2015
DOI:10.1039/C5AY02095F
A kind of water-dispersible Pt nanoparticle–reduced graphene oxide hybrid material (Pt–rGO) has been prepared by in situ reduction of both graphene oxide (GO) and the Pt precursor in acidic solution using metallic Zn powder. Great amounts of highly dispersed Pt nanoparticles could be well loaded on the surface of the graphene, as revealed by transmission electron microscopy (TEM). In addition, the nanocomposites were also characterized by Fourier transform-infrared spectrometry (FT-IR), ultraviolet-visible absorption spectrometry (UV-Vis), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The experimental results demonstrated that the constructed sensor exhibited excellent catalytic activity toward H2O2, and obtained a wide linear range from 1.0 × 10−9 to 1.4 × 10−3 M with low limit of detection (LOD) of 3.4 × 10−10 M, which was superior to that obtained with other H2O2 electrochemical sensors reported previously. Furthermore, it can also be successfully applied to real sample analysis in human serum with satisfactory recoveries, and the electrocatalytic mechanism of the constructed sensor was briefly discussed.
Co-reporter:Qing Bi, Shuqing Dong, Yaming Sun, Xiaoquan Lu, Liang Zhao
Analytical Biochemistry 2016 Volume 508() pp:50-57
Publication Date(Web):1 September 2016
DOI:10.1016/j.ab.2016.05.022
Abstract
A novel electrochemical sensor based on 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanocrystals (TOCNCs) and l-cystines (l-Cys) modified Au electrode (TOCNC/l-Cys/Au) has been fabricated for detection and discrimination of the enantiomers of phenylalanine (Phe), leucine (Leu), and valine (Val). The three amino acids are in connection with metabolism diseases. The TOCNC/l-Cys/Au electrode exhibited obvious peak current difference for the amino acid enantiomers by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The TOCNCs on the electrode surface expressed different interactions with d- and l-amino acids, so the electrochemical recognitions of the three amino acid enantiomers were achieved. TOCNCs were characterized by Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM). The modified electrodes were characterized by SEM and electrochemical techniques. According to DPV, peak currents of the two enantiomers decreased linearly with their concentrations. Furthermore, satisfactory results were obtained when this electrode was applied to measure the d- and l-Phe mixture. The experimental results show that TOCNCs are suitable material for chiral sensor. The contrast of serum sample of healthy people and patients with type 2 diabetes also was proposed, and significant difference was exhibited on the modified electrode. This work is significant for the screening, diagnosis, and treatment of multiple metabolic diseases.
Co-reporter:Zhonghua Xue, Bo Yin, Mengqian Li, Honghong Rao, Hui Wang, Xibin Zhou, Xiuhui Liu, Xiaoquan Lu
Electrochimica Acta 2016 192() pp: 512-520
Publication Date(Web):20 February 2016
DOI:10.1016/j.electacta.2016.01.206
Many methods have been proposed for graphene production with good dispersion both in the drying state and in common solvents. In this work, a facile and convenient approach to synthesis of electrochemical reduction graphene oxide (ERGO) and nickel oxide nanoparticles composite through cyclic voltammetry is reported. The proposed method is fast, and green, no toxic solvents are used and therefore will not result in contamination of the as-prepared composites. The products have been successfully characterized by Scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction and Photoelectron spectroscopy, and electrochemical technology. The results show that well dispersed composites with layered nanostructures consisting of alternating layers of metal oxide nanoparticles and ERGO sheets can be achieved by the proposed strategy. A thin layer model is used to illustrate the effects of diffusion within the layered nanostructures. The obtained composites modified electrode exhibits superior catalytic performance for the target molecule of 2, 4, 6-trinitrophenol (TNP).
Co-reporter:Zhuang Li, Zhenzhen An, Yongyang Guo, Kangning Zhang, Xiaoling Chen, Dongxia Zhang, Zhonghua Xue, Xibin Zhou, Xiaoquan Lu
Talanta 2016 Volume 161() pp:713-720
Publication Date(Web):1 December 2016
DOI:10.1016/j.talanta.2016.09.033
•A novel and uniform Au-PtNPs/PyTS-NG nanocomposite was fabricated by direct electrodeposition method.•The prepared nanocomposite exhibited excellent catalytic activity to the oxidation of nitrite.•An amperometric sensor with a linear range of 0.5–1621 μM and a detection limit of 0.19 μM was set up.•Detection of nitrite in real samples was studied.In this work, we report a novel Au-Pt bimetallic nanoparticles (Au-PtNPs) decorated on the surface of nitrogen-doped graphene (NG) functionalized with 1, 3, 6, 8-pyrene tetra sulfonic acid sodium salt (PyTS) by direct electrodeposition method. The results of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and electrochemical impendence spectrum (EIS) reveal that the Au-PtNPs were successfully anchored on the surface of NG sheets with a diameter of 20–40 nm. Further, the prepared Au-PtNPs/PyTS-NG nanocomposite exhibits superior catalytic activity for the oxidation of nitrite. Under optimal experimental conditions, an amperometric sensor with a linear range of 0.5–1621 μM and a detection limit of 0.19 μM (S/N=3) for the detection of nitrite was set up and applied to real samples.
Co-reporter:Zhipan Guo, Xiuhui Liu, Yuelin Liu, Guofan Wu, Xiaoquan Lu
Biosensors and Bioelectronics 2016 Volume 86() pp:671-676
Publication Date(Web):15 December 2016
DOI:10.1016/j.bios.2016.07.033
•A novel 8-OHdG sensor based on MWCNTs/GCE was fabricated.•The sensor exhibited a super-low detection limit toward the 8-OHdG(18.8 nM).•The sensor can detect the 8-OHdG generated from the damaged DNA and guanine.•The work established an association between 8-OHdG and degree of DNA damage.8-Hydroxy-2′-deoxyguanosine (8-OHdG) is commonly identified as a biomarker of oxidative DNA damage. In this work, a novel and facile 8-OHdG sensor was developed based on the multi-walled carbon nanotubes (MWCNTs) modified glassy carbon electrode (GCE). It exhibited good electrochemical responses toward the oxidation of 8-OHdG, and the linear ranges were 5.63×10−8−6.08×10−6 M and 6.08×10−6−1.64×10−5 M, with the detection limit of 1.88×10−8 M (S/N=3). Moreover, the fabricated sensor was applied for the determination of 8-OHdG generated from damaged DNA and guanine, respectively, and the oxidation currents of 8-OHdG increased along with the damaged DNA and guanine within certain concentrations. These results could be used to evaluate the DNA damage, and provide useful information on diagnosing diseases caused by mutation and deficiency of the immunity system.
Co-reporter:Dong-Dong Qin, Xue-Huai Wang, Yang Li, Jing Gu, Xing-Ming Ning, Jing Chen, Xiao-Quan Lu, and Chun-Lan Tao
The Journal of Physical Chemistry C 2016 Volume 120(Issue 39) pp:22195-22201
Publication Date(Web):September 20, 2016
DOI:10.1021/acs.jpcc.6b06903
Elemental doping is an effective way to suppress charge recombination and modify the band gap of TiO2, therefore enhancing its photocatalytic activity. Here, we report a dual-doping method induced by a one-step novel low temperature (300 °C) PH3 annealing method for improving the photoelectrochemical performance of TiO2 nanorods grown on transparent conducting substrates. X-ray photoelectron spectroscopy (XPS) indicates that Ti4+ is completely converted to Ti3+ within a surface layer of TiO2 to a depth of about 20 nm following this treatment. In addition to Ti3+ self-doping, phosphorus ions in two different oxidation states (P5+ and P3–) are observed. Incorporation of these ions into TiO2 leads to an increase of 1 order of magnitude in the carrier density, resulting in faster transport and longer lifetimes of photogenerated electrons. Additionally, the valence band maximums of the PH3-treated rutile and anatase TiO2 shift toward the direction of the Fermi level by 0.92 and 0.42 eV, respectively, together with absorption change indicating successful band gap narrowing. This doping effect gives rise to extension of absorption to the longer wavelength and enhancement of the photoactivity of TiO2 photoelectrodes under visible light. Although the PH3 treatment increases the density of surface states and thus leads to a positive shift in the photocurrent onset potential and a lower charge injection efficiency, a greatly improved photocurrent of 1.8 mA·cm–2 at 1.23 V vs RHE (AM 1.5G, 100 mW·cm–2) for rutile TiO2 is seen. This is five times higher than the photocurrent observed for undoped control samples (as compared with 0.35 mA·cm–2 of the undoped control samples). The PH3 annealing strategy seems to be quite general and should have applications in improving the visible light photon absorptivity of other oxide semiconductors, especially those with wide band gaps.
Co-reporter:Jing Chen, Miao Zhang, Qing Ma, Dongdong Qin, Liping Zhang, Xiaoquan Lu
Chemometrics and Intelligent Laboratory Systems 2016 150() pp: 23-28
Publication Date(Web):15 January 2016
DOI:10.1016/j.chemolab.2015.10.014
•The QSAR model of the pyrazolo[1,5-a]pyrimidine derivative inhibitors of Chk1 is constructed by PSO-SVM.•The stepwise multiple linear regression method is used to select the descriptors.•A stable model can be constructed by JG14, G3s, R8u+ and RDF085e.•The PSO-SVM has higher stability and better prediction performance.Checkpoint kinase 1 (Chk1) is a serine/threonine kinase that plays a key role in the response to DNA-mediated cell injury. In this paper, the quantitative structure–activity relationship (QSAR) models were constructed to predict the activity of pyrazolo[1,5-a]pyrimidine derivatives of Checkpoint kinase 1 (Chk1) by using SVM and PSO-SVM methods. The root-mean-square errors (RMSE) of the training set and the test set for the PSO-SVM model were 0.0886 and 0.1803, respectively. For the SVM model, the values were 0.2185 and 0.4023, respectively. The results showed that the performance of the PSO-SVM model was better than the corresponding SVM model. Thus, it can be inferred that the PSO-SVM analysis will be a promising method and be spread to apply in the QSAR studies.
Co-reporter:Xingming Ning
The Journal of Physical Chemistry C 2016 Volume 120(Issue 2) pp:919-926
Publication Date(Web):December 28, 2015
DOI:10.1021/acs.jpcc.5b11246
Inspired by the spatial elaborate architecture and the kinetics characteristic of the nature photosynthesis, a nanohybrid of Au@THPP/CNTs with columnar-like shape has been prepared by a combination of the gold-4-hydroxyphenyl porphyrin nanohybrid of core–shell structure (Au@THPP) and vertically aligned carbon nanotubes (CNTs) grown on a transparent conducting substrate. A simplified model to uncover the partial electron transfer (ET) of photosystem II (PSII) using the nanohybrid by the chemical approach has been set up. The UV–vis/scanning electrochemical microscopy (UV–vis/SECM) platform, a simple, effective, and novel electrochemistry method, was used to investigate the behavior of photoinduced electron transfer of the model. At 560 nm wavelength, the heterogeneous electron transfer rate constant (keff) of this model is the highest, which is consistent with the maximum absorption wavelength of a different chromophore achieved in photosynthesis. The model is not only of great value to study the complex photosynthesis but also of potential application in a biomimetic system.
Co-reporter:Zhonghua Xue, Huihui Hou, Honghong Rao, Chenxian Hu, Xibin Zhou, Xiuhui Liu and Xiaoquan Lu
RSC Advances 2015 vol. 5(Issue 46) pp:36707-36714
Publication Date(Web):15 Apr 2015
DOI:10.1039/C5RA02737C
Here, we demonstrate the fabrication of reduced graphene oxide films on different carbon-based substrates including glassy carbon electrodes (GCEs), graphite electrodes, and carbon paste electrodes through a green approach via a direct electro-deposition technique. The resulting electrochemically reduced graphene oxide (ERGO) films have been investigated by scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The as-prepared ERGO film modified electrodes show different and significant electrocatalytic activity toward nitrite oxidation. Among them, the ERGO film modified GCE (ERGO/GCE) has been proven to function as electron transfer mediator and possess high electrocatalytic activity, stability and sensitivity, which might be attributed to the unique structural features of ERGO/GCE.
Co-reporter:Yidan Liu, Xiuhui Liu, Ming Li, Yuelin Liu, Zhipan Guo, Zhonghua Xue and Xiaoquan Lu
RSC Advances 2015 vol. 5(Issue 121) pp:100268-100271
Publication Date(Web):17 Nov 2015
DOI:10.1039/C5RA17717K
In this communication we present the innovative synthesis of porous graphene (PGN) using silver nanoparticles (AgNPs) etching. The PGN material with large specific area and good biocompatible was used to load on great amount of enzyme, horseradish peroxidase (HRP), to fabricate an amperometric sensor. The constructed electrode displayed good electrocatalytic activity toward H2O2 reduction, and the peak current was 4.8 times as large as that of bare glassy carbon electrode. Moreover, the electrocatalytic mechanism of H2O2 reduction on HRP/PGN/GC electrode was also explored.
Co-reporter:Ai Luo, Qianwen Lian, Zhenzhen An, Zhuang Li, Yongyang Guo, Dongxia Zhang, Zhonghua Xue, Xibin Zhou, Xiaoquan Lu
Journal of Electroanalytical Chemistry 2015 Volume 756() pp:22-29
Publication Date(Web):1 November 2015
DOI:10.1016/j.jelechem.2015.08.008
•A novel PyTS–NG nanocomposite was successfully prepared.•The material has better dispersivity and conductivity.•A sensitive electrochemical sensor based on PyTS–NG was fabricated for simultaneous determination of UA, XA and HX.A highly sensitive and selective method was developed for simultaneous detection of uric acid (UA), xanthine (XA) and hypoxanthine (HX) based on a 1,3,6,8-pyrene tetra sulfonic acid sodium salt functionalized nitrogen-doped graphene (PyTS–NG) composite. The material was synthesized by utilizing a facile ultrasonic method via π–π conjugate action between 1,3,6,8-pyrene tetra sulfonic acid sodium salt (PyTS) and nitrogen-doped graphene (NG) molecule. Compared with pristine NG, the material had better dispersivity and conductivity, which might be attributed to a large number of edge-plane-like defective sites on the surface of PyTS–NG that would accelerate electron transfer between electrode and species in solution. The surface morphology was characterized by scanning electron microscopy and transmission electron microscopy. The electrochemical behaviors of UA, XA and HX on the surface of PyTS–NG were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under the optimized condition, the linear ranges for the determination of UA, XA and HX were 9–1000, 8–800 and 8–200 μM, with the detection limits (S/N = 3) of 0.331, 0.0838 and 0.231 μM, respectively. Furthermore, the practical application of the present method was evidenced by determining UA, XA and HX in human blood serum and urine samples.
Co-reporter:Qianwen Lian, Ai Luo, Zhenzhen An, Zhuang Li, Yongyang Guo, Dongxia Zhang, Zhonghua Xue, Xibin Zhou, Xiaoquan Lu
Applied Surface Science 2015 Volume 349() pp:184-189
Publication Date(Web):15 September 2015
DOI:10.1016/j.apsusc.2015.04.217
Highlights
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A novel AuNPs/Trp-GR composite was fabricated by directly electrochemical deposition.
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The composite exhibited excellent electrocatalytic activity towards DA.
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The proposed method was applied to real samples.
Co-reporter:Zhonghua Xue, Chenxian Hu, Honghong Rao, Xuemei Wang, Xibin Zhou, Xiuhui Liu and Xiaoquan Lu
Analytical Methods 2015 vol. 7(Issue 3) pp:1167-1174
Publication Date(Web):08 Dec 2014
DOI:10.1039/C4AY02537G
A novel electrochemical sensor for capsaicin using mesoporous cellular foams (MCFs) as the sensitive material is reported. The surface morphology and electrochemical properties of the prepared MCFs modified carbon paste electrode (CPE) were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The proposed modified electrode shows high sensitivity towards the oxidation of capsaicin in 0.1 M perchloric acid solutions (pH 1.0). Under optimized conditions, the electrochemical oxidation current of capsaicin was found to be linearly related to the concentration over the range 0.76 to 11.65 μM with a correlation coefficient of 0.9990, and the detection limit was found to be 0.08 μM at a signal-to-noise ratio of 3. The proposed electrochemical sensor was successfully applied to the determination of capsaicin by using standard addition method with satisfactory results.
Co-reporter:Baomei Huang, Xibin Zhou, Jing Chen, Guofan Wu, Xiaoquan Lu
Talanta 2015 Volume 142() pp:228-234
Publication Date(Web):1 September 2015
DOI:10.1016/j.talanta.2015.04.053
•MMIP was first used to selectively enrich malachite green (MG) from fish samples.•This is the first paper combining MMIP with ECL for trace MG determination.•The limit of detection (LOD) of this method was 7.3 ng/kg (S/N=3).A novel procedure for selective extraction of malachite green (MG) from fish samples was set up by using magnetic molecularly imprinted polymers (MMIP) as the solid phase extraction material followed by electrochemiluminescence (ECL) determination. MMIP was prepared by using Fe3O4 magnetite as magnetic component, MG as template molecule, methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent. MMIP was characterized by SEM, TEM, FT-IR, VSM and XRD. Leucomalachite green (LMG) was oxidized in situ to MG by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). And then MMIP was successfully used to selectively enrich MG from fish samples. Adsorbed MG was desorbed and determined by ECL. Under the optimal conditions, calibration curve was good linear in the range of 0.29–290 μg/kg and the limit of detection (LOD) was 7.3 ng/kg (S/N=3). The recoveries of MMIP extraction were 77.1–101.2%. In addition, MMIP could be regenerated. To the best of our knowledge, MMIP coupling with ECL quenching of Ru(bpy)32+/TPA for the determination of MG has not yet been developed.Fe3O4 magnetite as magnetic component, MG as template molecule, methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as crosslinking agent, MMIP was prepared by bulk polymerization. And then MMIP was successfully used to selectively enrich MG from fish samples. The adsorbed MG was desorbed and determined by ECL.
Co-reporter:Jiao Du, Qinfeng Xu, Xiaoquan Lu, and Chun-yang Zhang
Analytical Chemistry 2014 Volume 86(Issue 16) pp:8481
Publication Date(Web):July 21, 2014
DOI:10.1021/ac502240c
Polynucleotide kinase (PNK) plays a crucial role in maintaining the genomic stability of cells and is becoming a potential target in the radio-therapeutic treatment of cancers. The fluorescent method is usually used to measure the PNK activity, but it is impossible to obtain the real-time monitoring without the employment of the labeled DNA probes. Here, we report a label-free bioluminescent sensor for PNK activity assay through real-time monitoring of the phosphorylation-dependent DNA ligation reaction. In this bioluminescent sensor, two hairpin DNA probes with 5′-protruding terminal are designed as the phosphate acceptor, and the widely used phosphate donor of ATP is substituted by dCTP. In the absence of PNK, the ligation reaction cannot be triggered due to the lack of 5′-phosphoryl groups in the probes, and the background signal is negligible. With the addition of PNK, the phosphorylation-ligation reaction of the probes is initiated with the release of AMP, and the subsequent conversion of AMP to ATP leads to the generation of distinct bioluminescence signal. The PNK activity assay can be performed in real time by continuously monitoring the bioluminescence signal. This bioluminescent sensor is much simpler, label-free, cost-effective, and free from the autofluorescence interference of biological matrix, and can be further used for quantitative, kinetic, and inhibition assay.
Co-reporter:Qianwen Lian, Zhifang He, Qian He, Ai Luo, Kaiwang Yan, Dongxia Zhang, Xiaoquan Lu, Xibin Zhou
Analytica Chimica Acta 2014 Volume 823() pp:32-39
Publication Date(Web):1 May 2014
DOI:10.1016/j.aca.2014.03.032
•Trp-GR was synthesized by utilizing a facile ultrasonic method.•The material as prepared had well dispersivity in water and better conductivity than pure GR.•Trp-GR/GCE showed excellent potential for the determination of AA, DA and UA.•The proposed method was applied for the analysis of AA, DA and UA in real samples.A new type of tryptophan-functionalized graphene nanocomposite (Trp-GR) was synthesized by utilizing a facile ultrasonic method via π–π conjugate action between graphene (GR) and tryptophan (Trp) molecule. The material as prepared had well dispersivity in water and better conductivity than pure GR. The surface morphology of Trp-GR was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The electrochemical behaviors of ascorbic acid (AA), dopamine (DA), and uric acid (UA) were investigated by cyclic voltammetry (CV) on the surface of Trp-GR. The separation of the oxidation peak potentials for AA–DA, DA–UA and UA–AA was about 182 mV, 125 mV and 307 mV, which allowed simultaneously determining AA, DA, and UA. Differential pulse voltammetery (DPV) was used for the determination of AA, DA, and UA in their mixture. Under optimum conditions, the linear response ranges for the determination of AA, DA, and UA were 0.2–12.9 mM, 0.5–110 μM, and 10–1000 μM, with the detection limits (S/N = 3) of 10.09 μM, 0.29 μM and 1.24 μM, respectively. Furthermore, the modified electrode was investigated for real sample analysis.
Co-reporter:Lichun Zheng, Xiuhui Liu, Min Zhou, Yongjun Ma, Guofan Wu, Xiaoquan Lu
Analytica Chimica Acta 2014 Volume 848() pp:67-73
Publication Date(Web):27 October 2014
DOI:10.1016/j.aca.2014.07.033
•A novel approach for ultrasensitive FI–CL detection of DNA sequences was developed.•A detection probe labeled with Ag+ was synthesized for the first time.•The method possesses high sensitivity and selectivity with a detection limit of 3.3 pM.We presented a new strategy for ultrasensitive detection of DNA sequences based on the novel detection probe which was labeled with Ag+ using metallothionein (MT) as a bridge. The assay relied on a sandwich-type DNA hybridization in which the DNA targets were first hybridized to the captured oligonucleotide probes immobilized on Fe3O4@Au composite magnetic nanoparticles (MNPs), and then the Ag+-modified detection probes were used to monitor the presence of the specific DNA targets. After being anchored on the hybrids, Ag+ was released down through acidic treatment and sensitively determined by a coupling flow injection–chemiluminescent reaction system (Ag+–Mn2+–K2S2O8–H3PO4–luminol) (FI–CL). The experiment results showed that the CL intensities increased linearly with the concentrations of DNA targets in the range from 10 to 500 pmol L−1 with a detection limit of 3.3 pmol L−1. The high sensitivity in this work may be ascribed to the high molar ratio of Ag+–MT, the sensitive determination of Ag+ by the coupling FI–CL reaction system and the perfect magnetic separation based on Fe3O4@Au composite MNPs. Moreover, the proposed strategy exhibited excellent selectivity against the mismatched DNA sequences and could be applied to real samples analysis.
Co-reporter:Bowan Wu, Lijie Hou, Miao Du, Tiantian Zhang, Zhihua Wang, Zhonghua Xue and Xiaoquan Lu
RSC Advances 2014 vol. 4(Issue 96) pp:53701-53710
Publication Date(Web):03 Oct 2014
DOI:10.1039/C4RA06210H
Functionalized gold nanoparticles (FuAuNP) have potential applications because of their specific functional groups. p-Aminothiophenol (p-ATP) possesses double functional groups that can be used to form an S–Au bond and oligoaniline. Based on molecular imprinting technology and electrochemical technology, a novel enzymeless methyl-parathion (MP) sensor has been constructed with nanocomposites. The template molecule (MP) is embedded in the imprinting sites by p-ATP molecular self-assembly and FuAuNP electro-polymerization. The imprinting effective sites and the conductive performance are improved by gold nanoparticles decorated carbon nanotube nanocomposites (AuNP–MCNT). The linear relationships between peak current and MP concentration are obtained in the range from 0.1 to 1.1 ng mL−1 and 1.1 to 11 ng mL−1, respectively. The detection limit can be achieved as low as 0.08 ng mL−1 (3σ) with relative standard deviation of 3.8% (n = 5). This sensor was also applied for the detection of MP in apples and vegetables, with average recoveries between 95.2% and 105.7% (RSD < 5%). The results mentioned above show that the novel electrochemical sensor is an ideal device for the real-time determination of MP in real samples.
Co-reporter:Zhonghua Xue, Yanjun Feng, Huixia Guo, Chenxian Hu, Ahmed Mahmoud idris Mohmed, Jinshu Li and Xiaoquan Lu
RSC Advances 2014 vol. 4(Issue 12) pp:5849-5852
Publication Date(Web):15 Nov 2013
DOI:10.1039/C3RA45677C
A novel electrocatalytic platform based on 5,15-bis (p-amino)-tetraphenylporphyrin (BATPP)/α-Al2O3 composites (sensitive materials) coated on glassy carbon electrodes, which was constructed by a simple electrochemical method, is reported. The directly simultaneous electrocatalytic oxidation and selective voltammetric peak separation of a mixture including ascorbic acid (AA), dopamine (DA) and uric acid (UA) in a phosphate buffer solution was investigated. The results showed that the platform resolved the overlapping voltammetric responses of AA, DA and UA with potential differences of 136 mV (AA to DA), 143 mV (DA to UA) and 279 mV (AA and UA) for cyclic voltammetry (CV). These results will open new opportunities for the development of an electrochemical sensor for the simultaneous determination of DA, UA and AA in real sample analyses in future.
Co-reporter:Cai-Xia Yuan, Yan-Ru Fan, Tao-Zhang, Hui-Xia Guo, Jing-Xuan Zhang, Yong-Lan Wang, Duo-Liang Shan, Xiao-Quan Lu
Biosensors and Bioelectronics 2014 Volume 58() pp:85-91
Publication Date(Web):15 August 2014
DOI:10.1016/j.bios.2014.01.041
•Nanostructured Pt–Pd NPs supported on conducting graphene nanosheets (rGO) and functionalized multiwalled carbon nanotubes (CNTs) to form a three-dimensional (3D) porous structural nanocomposite (marked as Pt–Pd NPs/CNTs–rGO) has been prepared via a facile and versatile hydrothermal synthetic strategy.•PCA can effectively anchor and stabilize the metal NPs in situ through its carboxy groups without using any other chemical reductant in synthesis process.•Utilizing CNTs in the proposed nanocomposite not only prevented rGO nanosheets from restacking, which results in increase of the basal spacing between rGO sheets, but also increases the electrolyte/electrode contact area.In this study, an electrochemical sensor of nitro aromatic compound based on three-dimensional porous Pt–Pd nanoparticles (Pt–Pd NPs) supported by reduced graphene oxide (rGO) nanosheets–multiwalled carbon nanotube (CNTs) nanocomposite (marked as Pt–Pd NPs/CNTs–rGO) was investigated for the first time. This hybrid nanocomposite has been prepared via a facile and versatile hydrothermal synthetic strategy while its structure and property are evaluated by X-ray diffraction (XRD), transmission electron microscopy (TEM) and electrochemical impedance spectroscopy (EIS). The result shows that 3D porous Pt–Pd NPs/CNTs–rGO nanocomposite has a large specific surface area of 326.6 m2 g−1 and exhibited ultrahigh rate capability and good cycling properties at high rates. Electrochemical studies have been performed for the nitro aromatic compounds detection by using different pulse voltammetry (DPV) techniques. The proposed nanocomposite exhibited much enhanced elctrocatalytic activity and high sensitivity toward the detection of nitro aromatic compounds which compared with Pt–Pd NPs dispersed on functionalized rGO, Pt–Pd NPs dispersed on functionalized CNTs, rGO–CNTs and bare glass carbon electrode (GCE). On the basis of the above synergetic electrochemical sensing and synthesis procedure, the hybrid material can be recommended as a robust material for sensor-related applications. Moreover, the proposed sensor exhibits high reproducibility, long-time storage stability and satisfactory anti-interference ability.
Co-reporter:Xibin Zhou, Zhifang He, Qianwen Lian, Zhao Li, Huan Jiang, Xiaoquan Lu
Sensors and Actuators B: Chemical 2014 193() pp: 198-204
Publication Date(Web):
DOI:10.1016/j.snb.2013.11.085
Co-reporter:Xiaoyan Li, Xiuhui Liu, Weiwei Wang, Lin Li, Xiaoquan Lu
Biosensors and Bioelectronics 2014 59() pp: 221-226
Publication Date(Web):
DOI:10.1016/j.bios.2014.03.046
Co-reporter:Jing RU, Jie DU, Hong-Xia HE, Xiao-Quan LU
Chinese Journal of Analytical Chemistry 2013 Volume 41(Issue 8) pp:1249-1253
Publication Date(Web):August 2013
DOI:10.1016/S1872-2040(13)60674-X
The multi-dimension network of sol-gel SiO2 was immobilized on an electrode surface employing sol-gel and electrochemical impedance spectroscopy (EIS) techniques under the optimal experimental conditions. Then, the multi-dimension network structure of sol-gel was used to simulate electron transfer in cell membrane of micro interface. The electron transfer model was constructed successfully on the multi-dimension micro interface. These SiO2 materials exhibited tunable porosity, high thermal stability and chemical inertness.The multi-dimension network of sol-gel SiO2 was immobilized on the electrode surface using the sol-gel technique to simulate electron transfer in cell membrane of micro interface. The electron transfer model was constructed successfully on the multi-dimension micro interface and the SiO2 materials exhibited the advantages of tunable porosity, high thermal stability and chemical inertness under the conditions tested.
Co-reporter:Jing Ru, Jie Du, Dong-Dong Qin, Bao-Mei Huang, Zhong-Hua Xue, Xi-Bin Zhou, Xiao-Quan Lu
Talanta 2013 Volume 110() pp:15-20
Publication Date(Web):15 June 2013
DOI:10.1016/j.talanta.2013.03.038
Co-reporter:Xiaoquan Lu, Duoliang Shan, Jianmin Yang, Baomei Huang, Xibin Zhou
Talanta 2013 Volume 115() pp:457-461
Publication Date(Web):15 October 2013
DOI:10.1016/j.talanta.2013.06.002
•The thiol–ene chemistry guided preparation of a novel mixed-thiolated conducting polymers.•Fullerenols and PANI improved the electrochemical response of m-DNB.•A highly sensitive detection of m-DNB was proposed.A novel sensor based on thiol-porphyrin mixed monolayer-tethered polyaniline (PANI) with intercalating fullerenols was applied to sensitively detect m-dinitrobenzene (m-DNB) by differential pulse voltammetry (DPV). The thiolated polyaniline was examined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrode modification of thiol-porphyrin mixed monolayer-tethered polyaniline with intercalating fullerenols exhibited a higher analytical sensitivity versus that of thiol-porphyrin mixed monolayer-tethered polyaniline, because the fullerenols in mixed monolayer could improve the preconcentration efficiencies of m-DNB. Under optimum conditions, the linear calibration curves ranged from 0.029 to 10,000 nmol L−1 for m-DNB, with a limit of detection (S/N=3) of 9.72 pmol L−1.The preparation of the fullerenols/PANI-mixed-thiol film. (a) Bare GCE, (b) PANI/GCE, (c) PANI-mixed-thiol/GCE, and (d) fullerenols/PANI-mixed-thiol/GCE.A novel mixed-thiolated conducting polymer (PANI) was prepared firstly. The introduction of thiolated PANI improved the electrochemical response of m-DNB. Then fullerenols were intercalated in the PANI-mixed-thiol film. The electron-rich hydroxyl group of fullerenols could interact with the electron-deficient nitro-group of m-DNB, and improved the electrochemical response of m-DNB.
Co-reporter:Xiuhui Liu, Zhihan Nan, Yu Qiu, Lichun Zheng, Xiaoquan Lu
Electrochimica Acta 2013 90() pp: 203-209
Publication Date(Web):
DOI:10.1016/j.electacta.2012.11.119
Co-reporter:Hong Xia, Dongdong Qin, Xibin Zhou, Xiuhui Liu, and Xiaoquan Lu
The Journal of Physical Chemistry C 2013 Volume 117(Issue 45) pp:23522-23528
Publication Date(Web):October 21, 2013
DOI:10.1021/jp407760m
Ion transport is especially crucial in normal body function, which is regulated by specialized ion channels. In this report, the simple hydrophilic alumina nanochannel is constructed at liquid/liquid (L/L) interface to simulate veritably and compactly complex cross-channel ion transfer processes of living systems in a similar physiological saline environment. The selectivity and regulation that are known for being two important characteristics of ion channels were achieved due to controllable electrosurface properties of alumina nanochannel. This channel shows good selectivity for ion with low electronegativity. The regulatory role of ion channel in confined space was achieved by varying diameters of nanochannel and lengths of ions travel path. In addition, a new theory based on the Randles-Sevcik equation is proposed for evaluation of cross-channel ion transfer in this article for the first time. The ingenious design strategy is demonstrated to be a useful means for investigating the complex cross-channel ion transport.
Co-reporter:Baomei Huang, Xibin Zhou, Zhonghua Xue, Xiaoquan Lu
TrAC Trends in Analytical Chemistry 2013 Volume 51() pp:107-116
Publication Date(Web):November 2013
DOI:10.1016/j.trac.2013.06.012
•First review of electrochemiluminescence (ECL) quenching of Ru(bpy)32+.•This review presents the state of ECL quenching of Ru(bpy)32+.•We discuss in detail the ECL-quenching co-reactants of Ru(bpy)32+.•We discuss in detail the ECL-quenching mechanism.•We discuss applying ECL quenching coupled with separation techniques.Electrochemiluminescence (ECL) of tris(2,2′-bipyridyl)ruthenium [Ru(bpy)32+] has received considerable attention over broad applications due to its remarkably high sensitivity and extremely wide dynamic range.This review presents the state of ECL quenching of Ru(bpy)32+. After a brief introduction of the ECL of Ru(bpy)32+, we discuss in detail ECL-quenching co-reactants, the ECL-quenching mechanism and applications of ECL quenching coupled with capillary electrophoresis and flow-injection analysis.
Co-reporter:Hongxia He, Jie Du, Yaqi Hu, Jing Ru, Xiaoquan Lu
Talanta 2013 Volume 115() pp:381-385
Publication Date(Web):15 October 2013
DOI:10.1016/j.talanta.2013.05.054
•Traditional electrochemical methods are unsuitable for intracellular GSH detection.•NiHCF/CTAB/AuNPs film was successfully prepared by electrodepositing method.•NiHCF/CTAB/AuNPs Pt UME had a sensitive respond toward the oxidation of GSH.•The microsensor could be used to give in situ information on the GSH concentration.A novel method for glutathione (GSH) detection in real blood sample with a nickel hexacyanoferrate (NiHCF) film modified Pt ultramicroelectrode (UME) was proposed. The electrochemical properties of NiHCF film modified Pt UME were improved by introducing cetyltrimethylammonium bromide (CTAB) and Au nanoparticles (AuNPs) into NiHCF film. The novel hybrid films (NiHCF/CTAB/AuNPs) were prepared by electrodepositing NiHCF and AuNPs in the presence of CTAB on the surface of Pt UME. The results indicated that the prepared NiHCF/CTAB/AuNPs Pt UME had a sensitive respond toward the oxidation of GSH and could be used for its selective determination in the presence of other coexisting interferents in real blood samples. The calibration curve for GSH was found to be linear from 0.2–1 μM, and the limit of detection (S/N=3) was 0.08 μM. The strategy explored here might provide a new pathway to design NiHCF/CTAB/AuNPs film microsensor for in situ detecting GSH, which had unique characteristics and potential applications in the fields of sensor and medical diagnosis.
Co-reporter:Xiuhui Liu, Caihong Bu, Zhihan Nan, Lichun Zheng, Yu Qiu, Xiaoquan Lu
Talanta 2013 Volume 105() pp:63-68
Publication Date(Web):15 February 2013
DOI:10.1016/j.talanta.2012.11.059
We report on a new approach for the electrochemical detection of hydrogen peroxide (H2O2) based on Cytochrome C (Cyt c) immobilized ionic liquid (IL)-functionalized multi-walled carbon nanotubes (MWCNTs) modified glass carbon electrode (GCE). Functionalization of multi-walled carbon nanotube with amine-terminated ionic liquid materials was characterized using fourier transform infrared spectroscopy (FTIR), UV–vis spectra, and electrochemical impedance spectroscopy (EIS), and the results showed that the covalent modification of MWCNTs with ILs exhibited a high surface area for enzyme immobilization and provided a good microenvironment for Cyt c to retain its bioelectrocatalytic activity toward H2O2. Amperometry was used to evaluate the catalytic activity of the cyt c towards H2O2. The proposed biosensor exhibited a wide linear response range nearly 4 orders of magnitude of H2O2 (4.0×10−8 M–1.0×10−4 M) with a good linearity (0.9980) and a low detection limit of 1.3×10−8 M (based on S/N=3). Furthermore, the biosensor also displays some other excellent characteristics such as high selectivity, good reproducibility and long-term stability. Thus, the biosensor constructed in this study has great potential for detecting H2O2 in the complex biosystems.Highlights► Amine-terminated IL-functionalized MWCNTs modified electrode was fabricated. ► It exhibits a high surface area for enzyme immobilization. ► Cyt c-MWNT-IL-GCE greatly enhanced the electrochemical response of H2O2. ► Linearity of H2O2 signals ranged from 0.04 to 100 μm.
Co-reporter:Xiaoquan Lu, Yaqi Hu, Wenting Wang, Jie Du, Hongxia He, Ruixia Ai, Xiuhui Liu
Colloids and Surfaces B: Biointerfaces 2013 Volume 103() pp:608-614
Publication Date(Web):1 March 2013
DOI:10.1016/j.colsurfb.2012.11.013
Photoinduced electron transfer with the electron donor–acceptor linked system of zinc-5,10,15,20-tetraphenylporphyrin (ZnTPP) as donor and benzoquinone (BQ) as acceptor was designed to mimic the electron transfer process in photosynthetic reaction center. Within the framework of the bimolecular electron transfer mechanisms of scanning electrochemical microscopy (SECM), the fundamental features of photoinduced electron transfer were demonstrated by recording the feedback approach curves under different light wavelength, intensity, and concentration of BQ. Meanwhile, relevant theoretical study was employed to support our proposal. It demonstrated that SECM as a new platform could also provide crucial information for simple simulation of the electron transfer process in photosynthetic reaction center.Graphical abstractPhotoinduced electron transfer with the electron donor–acceptor linked systems of porphyrin as donor and benzoquinone as acceptor was designed to simply mimic the electron transfer process in photosynthetic reaction center.Highlights► Photoinduced donor–acceptor electron transfer was studied by SECM. ► SECM mode was applied for simple simulation about natural electron transfer process. ► A photoelectrochemical sensing could be constructed based on the research.
Co-reporter:Xiaoquan Lu, Yan Li, Xia Zhang, Jie Du, Xibin Zhou, Zhonghua Xue, Xiuhui Liu
Analytica Chimica Acta 2012 Volume 711() pp:40-45
Publication Date(Web):20 January 2012
DOI:10.1016/j.aca.2011.11.005
We demonstrate that core–shell multi-component nanocomposites can be grown in situ at room temperature by a novel one-step approach without adding any reductant and stabilizer. We have presented a one-step method for the synthesis of multi-component nanocomposites in water solution, the multi-component nanocomposites could be produced directly and quickly in an in situ wet-chemical reaction. Here, Au–polypyrrole (PPy)/Prussian blue (PB) nanocomposites have been synthesized successfully under the same circumstance. With the addition of pyrrole monomers into mixture solutions, the autopolymerization of pyrrole into PPy and AuCl4− was reduced to elemental Au instantaneously as well as simultaneously. At the same time, PB produced along with elemental Au serving as a catalyst. Furthermore, we investigated the performance of Au–PPy/PB nanocomposites as amperometric sensor toward the reduction of H2O2, which displayed high sensitivity, fast response and good stability. The peak current of H2O2 increased linearly with the concentration of H2O2 in the range from 2.5 × 10−9 to 1.2 × 10−6 M, and the low detection limit of 8.3 × 10−10 M (S/N = 3) was obtained. Therefore, this work provides a new pathway to design and fabricate novel multi-component nanocomposites, which have unique characteristics and hold great applications in the fields of sensors, electrocatalysis and others.Graphical abstractThis scheme is a brief synthetic procedure and the chemical structure of the Au–PPy/PB core-shell nanocomposites. With the addition of pyrrole monomers, pyrrole was autopolymerization to PPy and AuCl4− was reduced to elemental Au instantaneously and simultaneously, and more excitedly, PB was produced along with elemental Au serving as a catalyst.Highlights► Au–PPy/PB nanocomposites can be grown quickly and directly by a one-step method. ► There is no adding any reductant and stabilizer in the synthesis progress. ► The novel one-step method is facile, environmentally benign and available. ► Au–PPy/PB nanocomposites are used to construct a stable and sensitive H2O2 sensor.
Co-reporter:Wenting Wang, Yaqi Hu, Chunming Wang, Xiaoquan Lu
Electrochimica Acta 2012 Volume 65() pp:244-250
Publication Date(Web):30 March 2012
DOI:10.1016/j.electacta.2012.01.049
The electrochemical behaviors of self-assembled substituted porphyrins (SH-terminated, abbreviated as H2TPPO(CH2)nSH, n = 3, 12) on a gold electrode were investigated using the steady-state scanning electrochemical microscopy (SECM). The different electron-transfer (ET) kinetics, including the bimolecular ET between the porphyrin self-assembled monolayers (SAMs) and the redox mediator [K3Fe(CN)6], the tunneling ET between the underlying gold electrode and [K3Fe(CN)6], and pinholes or defects, were clearly distinguishable. The SECM strategy was developed to deal with the two types of porphyrin SAMs. First, a model using alkanethiols [(CH2)nSH, n = 3, 12] as the functional template was proposed to change the conformation of porphyrin SAMs in a unit area of the electrode. Second, the porphyrin SAMs were directly prepared by inserting a metal (cobalt) into the center of the porphyrin ring. The results show the distinct effect of the presence of alkanethiols on the kinetics of the different-chain length porphyrins. In addition, the rate constants of the bimolecular ET significantly increased after the insertion of cobalt. The results are in agreement with the density functional theory (DFT).Highlights► Alkanethiols as the functional template was proposed to change the conformation of large end groups-porphyrins SAMs. ► Metal porphyrin SAMs was prepared to study the electron transport (ET) pathways. ► Distinguished different electron transport (ET) pathways and calculate relative rate constants by SECM. ► Bimolecular reaction as a model could be used to mimic ET process in chloroplasts or the important bio-molecular reaction in nature.
Co-reporter:Xiuhui Liu, Yijun Zhang, Yuehua He, Dafang Ji, Yongcheng Wang, Zhihua Wang, Xiaoquan Lu
Journal of Electroanalytical Chemistry 2012 Volume 671() pp:1-6
Publication Date(Web):15 April 2012
DOI:10.1016/j.jelechem.2012.02.021
A new oscillatory phenomenon based on Fe3+/Fe2+ was investigated systematically at the water/1,2-dichloroethane (W/DCE) interface by cyclic voltammetric technique. We focus our attention on study the concentrations of Fe3+/Fe2+ influence on oscillatory phenomena appearance in this paper. It was found that the current oscillation only occurred in the site of oxidation peak of Fe2+, and was related to the concentration of Fe3+ in the aqueous phase, indicating that the oscillation is caused by the specific adsorption of ion pairs at the liquid–liquid interface between Fe3+ in the aqueous phase and TPB− in the organic phase. Furthermore, DFT theory was used to calculate the mechanism of ion pair formation for the first time. The result suggested that TPB−Fe3+TPB− ion pair has the lowest-energy state, which provided qualitative support for ion pair embodied state. Combining experiment results and theoretical calculation, a specific adsorption of ion pair model on liquid/liquid interface was proposed and a mechanism for the observed current oscillation is also discussed in this paper. In addition, a spectrophotometric experiment was performed to evidence a strong attractive interaction between Fe3+ and TPB−.Highlights► We report a novel oscillatory phenomenon for Fe3+/Fe2+ at W/DCE interface. ► The irregular current spikes observed mainly related to Fe3+ and TPB− concentrations. ► A specific adsorption of ion pair model was proposed for explain the oscillation. ► DFT calculation and the UV spectra provided support for the ion pair model.
Co-reporter:Bowan Wu, Zhihua Wang, Dongxia Zhao, Xiaoquan Lu
Talanta 2012 Volume 101() pp:374-381
Publication Date(Web):15 November 2012
DOI:10.1016/j.talanta.2012.09.044
A novel molecularly imprinted (MIP) impedimetric sensor was promoted for selective detecting melamine (MEL). The Au electrode modified with MIP poly (2-mercaptobenzimidazole) (PMBI) was prepared by electrochemical polymerization of 2-mercaptobenzimidazole (2-MBI) with cyclic voltammetry (CV) in the presence of template molecule MEL. The surface morphology and structure of MIP PMBI are characterized by atomic force microscopy (AFM), infrared spectra (IR), electrochemical impedance spectroscopy (EIS), and CV. The main driving force of recognition is the π-donor–acceptor interaction between MEL and PMBI. The imprinted electrode could avoid the interference successfully. In addition, a linear response curve was obtained from 1.0×10−8 M to 5.0×10−5 M, with the detection limit of 3.0×10−9 M. The sensor exhibits remarkable advantages, such as higher sensitivity, wider linear range and lower detection limit. The effective method has a potential application to monitor nonelectrochemically active substances in food analysis in the future.Highlights► We developed a novel MIP impedimetric sensor for melamine determination. ► The sensor was fabricated by electrochemical polymerization of 2-MBI MIPs films. ► The sensor is reusable and has great improvement in sensitivity and selectivity. ► It is a fast and real-time method for the detection of melamine in real samples. ► It is an effective method to monitor nonelectrochemically active substances.
Co-reporter:Xiaoquan Lu, Yao Li, Ping Sun, Bowan Wu, Zhonghua Xue, Xiuhui Liu, and Xibing Zhou
The Journal of Physical Chemistry C 2012 Volume 116(Issue 31) pp:16660-16665
Publication Date(Web):July 11, 2012
DOI:10.1021/jp3061043
The cyclic voltammetric behavior of metalloporphyrin species containing different substituents was investigated by thin-layer electrochemistry. In this paper, the two-step electron transfer between zinc porphyrin species containing different substituents in nitrobenzene and Fe(CN)64– in the aqueous phase was studied. The bimolecular rate constants for the two-step electron transfer reactions were obtained simultaneously by thin-layer theory. When we use the thin-layer theory to calculate the kinetics constants, the process of consecutive electron transfer is considered to be complete. However, this was not the case; by comparing the data that are calculated by Faraday’s law of electrolysis and the theory based on thin-layer cyclic voltammetry for consecutive electron transfer across the interface between two immiscible electrolyte solutions, the correction coefficient was obtained. The kinetics constants of multistep interfacial bimolecular reactions can be further calculated with more precision.
Co-reporter:Yanfeng Wang, Jie Du, Yaya Li, Duoliang Shan, Xibin Zhou, Zhonghua Xue, Xiaoquan Lu
Colloids and Surfaces B: Biointerfaces 2012 90() pp: 62-67
Publication Date(Web):
DOI:10.1016/j.colsurfb.2011.09.045
Co-reporter:Xiaoquan Lu, Hetong Qi, Xuefeng Zhang, Zhonghua Xue, Jun Jin, Xibing Zhou and Xiuhui Liu
Chemical Communications 2011 vol. 47(Issue 46) pp:12494-12496
Publication Date(Web):25 Oct 2011
DOI:10.1039/C1CC15697G
A facile carbon radical reaction procedure and a chemical reduction method were proposed to synthesize Ag nanoparticles on functionalized graphene with uniform, high dispersion and excellent stability. The resultant material showed excellent electrocatalytic activity to nitroaromatic compounds and high sensitivity to the detection of nitroaromatic compounds.
Co-reporter:Wenting Wang, Duoliang Shan, Yong Yang, Chunming Wang, Yaqi Hu and Xiaoquan Lu
Chemical Communications 2011 vol. 47(Issue 24) pp:6975-6977
Publication Date(Web):23 May 2011
DOI:10.1039/C1CC10842E
A new scanning electrochemical microscopy (SECM) model provided a two-dimensional quantitative analysis on a heterogeneous electron transport (ET) process of a functionalized porpyrin by photoinduced ET at the ITO/liquid interface. The basic features of oxidized porphyrin under light source were recorded by feedback approach curves within the framework of the bimolecular ET mechanisms.
Co-reporter:Jinfeng Wang, Jianxiao Gong, Yansong Xiong, Jiandong Yang, Yan Gao, Yaling Liu, Xiaoquan Lu and Zhiyong Tang
Chemical Communications 2011 vol. 47(Issue 24) pp:6894-6896
Publication Date(Web):20 May 2011
DOI:10.1039/C1CC11784J
We systematically explore the shape-dependent catalytic activities of Au nanocrystals toward glucose oxidation in alkaline electrolytes, which is strongly dependent on the shape of the Au nanocrystals. The {100}-bounded cubic Au nanocrystals are significantly more active than the {110}-bounded rhombic dodecahedral and {111}-bounded octahedral Au nanocrystals.
Co-reporter:Xiaoquan Lu, Yaya Li, Jie Du, Xibin Zhou, Zhonghua Xue, Xiuhui Liu, Zhihua Wang
Electrochimica Acta 2011 Volume 56(Issue 21) pp:7261-7266
Publication Date(Web):30 August 2011
DOI:10.1016/j.electacta.2011.06.056
A novel nanocomposites film of conducting polymers including single-walled carbon nanotubes (SWCNTs), polypyrrole (PPy) and gold nanoparticles (AuNPs) modified electrode has been applied in voltammetric sensors to detect epinephrine (EP) sensitively when ascorbic acids (AA) and uric acids (UA) exist. The nanocomposites film of conducting polymers which show an excellent electrocatalystic activity for the oxidation of EP and UA was characterized by scanning electron microscopy (SEM) and electrochemical methods. The catalytic peak currents obtained from differential pulse voltammetry (DPV) increased linearly with increasing EP concentrations in the range of 4.0 × 10−9–1.0 × 10−7 M with a detection limit of 2.0 × 10−9 M (S/N = 3), respectively. The results showed that the nanocomposites of conducting polymers can selectively determine EP in the coexistence of a large amount of UA and AA. In addition, the sensor exhibited excellent sensitivity, selectivity and stability. The PPy/AuNPs/SWCNTs nanocomposites film can also be satisfactorily used for detecting EP in epinephrine hydrochloride injection when contain AA and UA, which also shows good recovery for determination of EP in some biological fluids.Highlights• A novel PPy/AuNPs/SWCNTs nanomaterials biosensor was prepared to the selective determination of EP. • The methods we employed to prepare PPy/AuNPs/SWCNTs nanomaterials are extremely simple. • The PPy/AuNPs/SWCNTs nanocomposites biosensor we got from the results of experiments can totally eliminate the interference from AA and distinguish EP from UA.
Co-reporter:Xiaoquan Lu, Yanli Quan, Zhonghua Xue, Bowan Wu, Hetong Qi, Dong Liu
Colloids and Surfaces B: Biointerfaces 2011 Volume 88(Issue 1) pp:396-401
Publication Date(Web):1 November 2011
DOI:10.1016/j.colsurfb.2011.07.020
The hydroxide of meso-tetraphenylporphyrin derivatives functionalized carbon nanotubes (CNTs) was fabricated in our research to explore the interaction between porphyrin and explosive. It was turned out that in the formation of grid porphyrin film, carbon nanotubes as a cruciul base materials promoted the electron transfer rate. Most of important, the results also showed that the electrochemical response was enhanced through increasing the number of –OH substitution in porphyrin. Such information provides the platform for a practical strategy for rational design of the sensor of explosives.Graphical abstractSchematic representation of electrochemical sensing explosives. (A) The CNTs to glass carbon electrode surface; (B) the electropolymerization porphyrin to CNTs surface; (C) explosive adsorbs to the functionalized film; (D) electrochemical stripping detection of explosive..Highlights► The hydroxide of meso-tetraphenylporphyrin derivatives functionalized carbon nanotubes was successfully fabricated. ► Carbon nanotubes acted as the crucial base materials to form the grid porphyrin film. ► The electrochemical response to explosives was enhanced by increasing the number of –OH substitution in porphyrin. ► The ability of nanocomposite to detect explosive was attributed to the endemic preconcentration capability of CNTs and the strong electron donor of porphyrin.
Co-reporter:Xiaoquan Lu, Dongxia Zhao, Zhengen Song, Bowan Wu, Bingzhang Lu, Xibin Zhou, Zhonghua Xue
Biosensors and Bioelectronics 2011 Volume 27(Issue 1) pp:172-177
Publication Date(Web):15 September 2011
DOI:10.1016/j.bios.2011.06.043
Porphyrin is able to specifically combine with phosphorus, thus a novel bifunctional sensing platform for determination of porphyrin by visual colorimetry and electrochemistry was demonstrated. A pretreated gold sheet (or electrode) with 2-mercatpoethanol (2-ME) was chemically modified by POCl3 to obtain the surface phosphate active sites. The different stages of modified electrode were characterized by electrochemical impedance spectroscopy (EIS). The 1:1 cationic sitting-atop (SAT) complex P(V)–porphyrin was formed due to the high affinity of the modified gold sheet (or electrode) towards the porphyrin, resulting in electron transfer resistance increase of the electrode surface. Meanwhile, a dramatic color changing from burgundy to dark green of porphyrin solution was observed with the naked-eye within 3 s. What's more, this was reflected by the notable change of the Soret band of porphyrin when using UV–vis. Two sensing systems provide different sensitivity for porphyrin analysis. With visual colorimetry, porphyrin can be detected at a level of 1.0 × 10−6 M, whereas the detection limit of porphyrin is 3.0 × 10−8 M using the EIS method. The practical application of the sensor to determination of pheophytin which was obtained from fresh spinach leaves has been accomplished. The results demonstrate the facility and effectivity of our introduced bifunctional biosensor for quantitative analysis of porphyrin.Highlights► A feasible method of fabricating porphyrin bifunctional biosensor was developed byphosphate-based self-assembled monolayerfor the first time. ► Our research focuses on detecting porphyrin with two detection methods: visual colorimetry and electrochemistry. Visual colorimetry is one of the simplest microanalysis methods; it was employed to detect porphyrin via observed color change of porphyirn solution, which has advantages of rapidity, simpleness, high sensitiveness and easy miniaturization. Furthermore, the electrochemical impedance spectroscopy (EIS) has a good response for studying porphyrin and the resistance value is linearly dependent on the logarithm of porphyrin concentration within the range. ► Detailed mechanism of sensing porphyrin utilizing phosphate-based self-assembled monolayer was proposed in the methodology. ► In this work, the practical application of using the designed sensor to determine pheophytin obtained from fresh spinach leaves received satisfactory results. The results demonstrate the facility and effectivity of our introduced phosphate modified gold sheet (or electrode) for quantitative analysis of porphyrin.
Co-reporter:Xi Bin Zhou;Wen Jing Han;Jing Chen
Monatshefte für Chemie - Chemical Monthly 2011 Volume 142( Issue 9) pp:949-959
Publication Date(Web):2011 September
DOI:10.1007/s00706-011-0493-7
Studies on the interactions of antibiotic compounds with DNA can provide useful suggestions and guidance for the design of new and more efficient DNA-binding drugs. A quantitative structure–activity relationship (QSAR) study of the binding modes and binding affinities of the interactions between 30 antibiotic compounds and DNA was performed. A large number of descriptors that encode hydrophobic, topological, geometrical, and electronic properties were calculated to represent the structures of the antibiotic compounds. Aiming at a system with small, multidimensional samples, we utilized the genetic algorithm-support vector machine (GA-SVM) method to develop the QSAR, which can select an optimized feature subset and optimize SVM parameters simultaneously. A binary QSAR model for predicting binding mode and conventional QSAR models for predicting binding affinity were built based on the GA-SVM approach. The descriptors selected using GA-SVM represented the overall descriptor space and can account well for the binding nature of the considered dataset. The descriptors selected using the GA-SVM method were then used for developing conventional QSAR models by the artificial neural network (ANN) approach. A comparison between the conventional QSAR models using GA-SVM with those using ANN revealed that the former were much better. GA-SVM models can be useful for predicting binding modes and binding activities of the interactions of new antibiotic compounds with DNA.
Co-reporter:Zhihua Wang, Hui Li, Jing Chen, Zhonghua Xue, Bowan Wu, Xiaoquan Lu
Talanta 2011 Volume 85(Issue 3) pp:1672-1679
Publication Date(Web):15 September 2011
DOI:10.1016/j.talanta.2011.06.067
A novel electrochemical sensor based on molecularly imprinted polymer film has been developed for aspirin detection. The sensitive film was prepared by co-polymerization of p-aminothiophenol (p-ATP) and HAuCl4 on the Au electrode surface. First, p-ATP was self-assembled on the Au electrode surface by the formation of Au–S bonds. Then, the acetylsalicylic acid (ASA) template was assembled onto the monolayer of p-ATP through the hydrogen-bonding interaction between amino group (p-ATP) and oxygen (ASA). Finally, a conductive hybrid membrane was fabricated at the surface of Au electrode by the co-polymerization in the mixing solution containing additional p-ATP, HAuCl4 and ASA template. Meanwhile, the ASA was spontaneously imprinted into the poly-aminothiophenol gold nanoparticles (PATP–AuNPs) complex film. The amount of imprinted sites at the PATP–AuNPs film significantly increases due to the additional replenishment of ASA templates. With the significant increasing of imprinted sites and doped gold nanoparticles, the sensitivity of the molecular imprinted polymer (MIP) electrode gradually increased. The molecularly imprinted sensor was characterized by electrochemical impedance spectroscopy (EIS), differential pulse voltammetry (DPV), and cyclic voltammetry (CV). The linear relationships between current and logarithmic concentration were obtained in the range from 1 nmol L−1 to 0.1 μmol L−1 and 0.7 μmol L−1 to 0.1 mmol L−1. The detection limit of 0.3 nmol L−1 was achieved. This molecularly imprinted sensor for the determination of ASA has high sensitivity, good selectivity and reproducibility, with the testing in some biological fluids also has good selectivity and recovery.
Co-reporter:Xiaoquan Lu ; Tianxia Wang ; Xibing Zhou ; Yao Li ; Bowan Wu ;Xiuhui Liu
The Journal of Physical Chemistry C 2011 Volume 115(Issue 11) pp:4800-4805
Publication Date(Web):February 25, 2011
DOI:10.1021/jp111915y
In the nervous system, ion channels are essential for all processes. The highly ordered porous anodic aluminum oxide (AAO) was modified at the interface between two immiscible electrolyte solutions (ITIES) to recover the process of ion transfer through the ion channels. The study on dynamic process of ion transfer through the ion channels obtained for DK+0 is 1.40 × 10−8 cm2 s−1 and DNa+0 is 2.74 × 10−7 cm2s−1. The result offers tremendous advantages for linear relationship between the half-wave potential and concentration of K+ and Na+. In addition, it will be helpful to understand both the mechanism about the dynamics and thermodynamics processes of ion transfer through the ion channels and the role about ionic concentration in nerve conduction.
Co-reporter:Xiaoquan Lu, Ping Sun, Dongna Yao, Bowan Wu, Zhonghua Xue, Xibing Zhou, Ruiping Sun, Li Li, and Xiuhui Liu
Analytical Chemistry 2010 Volume 82(Issue 20) pp:8598
Publication Date(Web):September 20, 2010
DOI:10.1021/ac1016997
In this report, the theory based on thin-layer cyclic voltammetry (TLCV) for consecutive electron transfer (ET) across the interface between two immiscible electrolyte solutions (ITIES) is well developed and experimentally verified. The voltammetric responses to multistep electron transfer at the ITIES are predicted by numerical simulations. Moreover, the impact of empirical parameters on the shape of the multistep current−voltage curve has been examined. The results obtained not only give information regarding the effect of the concentration ratio of the reactants in two phases and the thin-layer thickness on multistep electron transfer, but also prove the excellent agreement between simulations and experiments. The model system of two-step electron transfer of ZnTPP/ [Fe(CN)6]4− was studied, indicating that the Bulter−Volmer (B−V) theory is suitable for the consecutive electron transfer. Thus, TLCV is demonstrated to be a useful means for investigating the kinetics of heterogeneous consecutive ET.
Co-reporter:Xiaoquan Lu, Junying Ma, Ruiping Sun, Mina Nan, Fanfu Meng, Jie Du, Xiaoyan Wang, Hui Shang
Electrochimica Acta 2010 Volume 56(Issue 1) pp:251-256
Publication Date(Web):15 December 2010
DOI:10.1016/j.electacta.2010.08.088
Substituent effects of iron porphyrin complexes on the structures and kinetic processes have been examined for the first time. Basing on the premise that iron porphyrin is functional analogous to heme, a series of iron porphyrin derivatives bearing different substituents at the meso positions of the corrole ring are investigated as to their electrochemistry, the relationships among the electron transfer (ET) processes, their structures, and orbital energies. The good coherence between the experiment and theory indicates that the ET rate can be accelerated when electron-donating substituents are introduced to the iron porphyrin ring. Finally, the implications of the results are discussed in the influence of stability of iron porphyrin complexes on the ability to carry molecular oxygen, which may suggest it possible to dominate the biological activity of heme by selecting the appropriate substituents to iron porphyrin ring.
Co-reporter:Xiaoquan Lu, Fupeng Zhi, Hui Shang, Xiaoyan Wang, Zhonghua Xue
Electrochimica Acta 2010 Volume 55(Issue 11) pp:3634-3642
Publication Date(Web):15 April 2010
DOI:10.1016/j.electacta.2009.11.004
Multilayers film of nanostructured gold nanoparticles (AuNPs) has been fabricated based on the layer-by-layer (LBL) technique using a self-assembled monolayer of 5,15-di-[p-(6-mercaptohexyl)-phenyl]-10,20-diphenylporphyrin (trans-PPS2). AuNPs act as physical cross-link points in the multilayers. Electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM) are applied to study the formation of the organic–inorganic multilayers film and have determined the electrochemical parameters, i.e., the heterogeneous electron transfer rate constant (Ket). The observed phenomena indicate that the electron transfer (ET) process is affected by material properties and the molecular structure of self-assembled monolayers (SAMs). Using the high sensitivity of ET of ferricyanide to the modification of the gold surface with multilayers film, we select this reaction as a probe to study the different modification stages at this modified electrode. ET is retarded on the trans-PPS2 alternative deposition of layers on the electrode surface and is accelerated on the AuNPs’ layers. SECM images are used to collect surface information in the course of the successive modification process. SECM images obtained from bare and different modification stages show very high resolution with different topographies.
Co-reporter:Xiao Quan Lu, Jun Ying Ma, Xiu Hui Liu, Cun Wu Dong, Wen Ting Wang
Chinese Chemical Letters 2010 Volume 21(Issue 1) pp:89-92
Publication Date(Web):January 2010
DOI:10.1016/j.cclet.2009.08.014
Comparison in electron transfer (ET) processes from decamethyferrocene (DMFe) in nitrobenzene (NB) to ferric ion in aqueous phase was investigated for the first time by the scanning electrochemical microscopy (SECM). As compared with the system of Fe(CN)63−–DMFe, the ET rate obtained from Fe3+–DMFe was lower in spite of larger driving force, which may arise from the effect of reorganization energy. Otherwise, the effect of common ion on rate constants was also probed and results suggested additional complexity of the ET mechanism between Fe(CN)63− and DMFe.
Co-reporter:Xiao Quan Lu, De Fang Dong, Xiu Hui Liu, Dong Na Yao, Wen Ting Wang, Yu Mei Xu
Chinese Chemical Letters 2010 Volume 21(Issue 2) pp:225-228
Publication Date(Web):February 2010
DOI:10.1016/j.cclet.2009.09.004
The oxidation of hydroquinone (QH2) was investigated for the first time at liquid/liquid (L/L) interface by scanning electrochemical microscopy (SECM). In this study, electron transfer (ET) from QH2 in aqueous to ferrocene (Fc) in nitrobenzene (NB) was probed. The apparent heterogeneous rate constants for ET reactions were obtained by fitting the experimental approach curves to the theoretical values. The results showed that the rate constants for oxidation reaction of QH2 were sensitive to the changes of the driving force, which increased as the driving force increased. In addition, factors that would affect ET of QH2 were studied. Experimental results indicated ion situation around QH2 molecule could change the magnitude of the rate constants because the capability of oxidation of QH2 would be affected by them.
Co-reporter:Jie Du, Yanfeng Wang, Xibin Zhou, Zhonghua Xue, Xiuhui Liu, Kun Sun and Xiaoquan Lu
The Journal of Physical Chemistry C 2010 Volume 114(Issue 35) pp:14786-14793
Publication Date(Web):August 17, 2010
DOI:10.1021/jp104796c
The electrochemical properties of a Prussian blue (PB) electrode were improved by introducing cetyltrimethylammonium bromide (CTAB) and Au nanoparticles (AuNPs) into PB films. The novel hybrid films (PB/CTAB/AuNPs) were fabricated by electrodepositing PB and AuNPs in the presence of CTAB. The electrochemical behavior of the hybrid film in some supporting electrolyte (cations for the K+, Na+, or K+/Na+) was investigated in detail, and well-defined and reversible voltammetric responses were obtained in Na+-based electrolytes. The catalytic activity of the PB/CTAB/AuNPs electrode toward hydrogen peroxide (H2O2) reduction at a neutral pH was also investigated, and the results indicated that the electrochemical reduction of H2O2 in the presence of physiological levels of Na+ was superior to that of a PB-modified electrode. Moreover, the PB/CTAB/AuNPs electrode exhibited good performance, a low detection limit (0.1 μM), and high stability at a wide range of concentrations (0.882−195 μM). To determine the performance of PB nanocomposite electrodes in Na+-based phosphate buffers, an amperometric biosensor with a PB/CTAB/AuNPs electrocatalyst was developed. To fabricate this sensor, the enzyme was immobilized in sol−gel and was electrodeposited onto a PB nanocomposite film. The results indicated that the biosensor can be used at a wide range of concentrations (20−400 μM) and possesses a low detection limit (7 μM) for glucose. These characteristics demonstrate that PB nanocomposite film can be used as an electron mediator for biosensors in potassium-free phosphate buffers.
Co-reporter:Jiandong Yang, Minrui Li, Hongxiang Li, Yanlian Yang, Yoshiaki Kashimura, Chen Wang, Keiichi Torimitsu, Xiaoquan Lu and Wenping Hu
The Journal of Physical Chemistry C 2010 Volume 114(Issue 28) pp:12320-12324
Publication Date(Web):June 24, 2010
DOI:10.1021/jp1020643
Self-assembled monolayers (SAMs) of thiol-derivatized porphyrin molecules on Au substrate have attracted extensive interest for use in sensing, molecular recognition, and molecular electronics. Here, we synthesized tetra[p-(3-mercaptopropyloxy)phenyl]porphyrin (PPS4) with four “clips” for SAMs. The results demonstrated that PPS4 could form excellent SAMs on gold surface wherein the molecules oriented on substrates with a tilted angle. Self-assembled nanojunctions of PPS4 were fabricated by using gold nanogap electrodes (gap width: ca. 100 nm), which exhibited nonlinear current−voltage characteristics, indicating tunneling injection of current from Au electrodes into PPS4. With the light on/off, the nanojunctions switched between low/high impedance states as nanometer scaled photoswitchers.
Co-reporter:Wenting Wang, Xiujuan Li, Xiaoyan Wang, Hui Shang, Xiuhui Liu and Xiaoquan Lu
The Journal of Physical Chemistry B 2010 Volume 114(Issue 32) pp:10436-10441
Publication Date(Web):July 27, 2010
DOI:10.1021/jp1026064
The synthetic sulfhydryl porphyrin compounds (abbreviated as H2TPPO(CH)nSH, n = 3, 4, 6, 9, 10, 12), with a systematic series of spacers containing large end groups−porphyrin rings and different length alkyl chains, were prepared to investigate the electron transport (ET) kinetics between a gold electrode modified with H2TPPO(CH)nSH and a redox mediator (ferricyanide). The three ET kinetics were clearly distinguishable by scanning electrochemical microscopy (SECM). As shown by the rate constants (kox) of bimolecular ET between H2TPPO(CH)nSH and the redox mediator, the rate constants (kb) of tunneling ET between the underlying gold electrode and the redox mediator, and the rate constants (k′) of pinhole or defects, ET depended upon alkyl chain length, surface coverage, and the concentration of the redox mediator. Among all of them, the bimolecular reaction which contained electron donor (mediators) and electron acceptor (SAMs) was a dynamic cyclic process. That strongly suggested that the bimolecular reaction should mimic ET of photosystem II in chloroplast.
Co-reporter:Tianlu Liao, Yanfeng Wang, Xibin Zhou, Yan Zhang, Xiuhui Liu, Jie Du, Xiujuan Li, Xiaoquan Lu
Colloids and Surfaces B: Biointerfaces 2010 Volume 76(Issue 1) pp:334-339
Publication Date(Web):1 March 2010
DOI:10.1016/j.colsurfb.2009.11.016
The detection of DNA damage is one of the most important topics in the DNA research fields. In this paper, an electrochemical method for the detection of DNA damage by combining the layer-by-layer assembly film with adriamycin (ADM) as an electrochemical probe was developed. Firstly, the layer-by-layer {dsDNA/PEI}n film was prepared by the alternate adsorption of polycationic polyethyleneimine (PEI) and negatively charged natural DNA onto glassy carbon electrode (GCE) surface. Its electrochemical behaviors were characterized by electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV), and the optimal value of n was determined to be 2. Secondly, the {dsDNA/PEI}2 film was immersed into the solution of ADM and the {dsDNA/PEI}2–ADM was obtained. While transferred into the blank solution, the {dsDNA/PEI}2–ADM would gradually release ADM, exhibiting the good reversibility of ADM incorporation. Finally, the DNA damage induced by styrene oxide (SO) was investigated and the promising results showed that the present method can be a useful tool for the detection of DNA damage.
Co-reporter:Xiu Hui Liu, Cun Wu Dong, Kai Zhang, Fu Peng Zhi, Zhen Ding, Xiao Quan Lu
Chinese Chemical Letters 2009 Volume 20(Issue 9) pp:1115-1118
Publication Date(Web):September 2009
DOI:10.1016/j.cclet.2009.04.035
Co-reporter:Jian-Ding Qiu, Jian-Hua Huang, Ru-Ping Liang, Xiao-Quan Lu
Analytical Biochemistry 2009 Volume 390(Issue 1) pp:68-73
Publication Date(Web):1 July 2009
DOI:10.1016/j.ab.2009.04.009
Being the largest family of cell surface receptors, G-protein-coupled receptors (GPCRs) are among the most frequent targets. The functions of many GPCRs are unknown, and it is both time-consuming and expensive to determine their ligands and signaling pathways by experimental methods. It is of great practical significance to develop an automated and reliable method for classification of GPCRs. In this study, a novel method based on the concept of Chou’s pseudo amino acid composition has been developed for predicting and recognizing GPCRs. The discrete wavelet transform was used to extract feature vectors from the hydrophobicity scales of amino acid to construct pseudo amino acid (PseAA) composition for training support vector machine. The prediction accuracies by the current method among the major families of GPCRs, subfamilies of class A, and types of amine receptors were 99.72%, 97.64%, and 99.20%, respectively, showing 9.4% to 18.0% improvement over other existing methods and indicating that the proposed method is a useful automated tool in identifying GPCRs.
Co-reporter:Jing Chen, Xiaoquan Lu
Talanta 2009 Volume 79(Issue 2) pp:129-133
Publication Date(Web):15 July 2009
DOI:10.1016/j.talanta.2009.02.022
This paper focuses on investigating the structure parameters of antibiotics which have decisive influence on the interactive mode between antibiotics and DNAs. The analytical results of Best Prediction Set Support Vector Machine Method (BPSSVM) show that the number of N atoms, the number of double bonds, the number of lone-pair electrons, the molar refractivity and the molecular radius are the main structure parameters which functionally decide their reactive modes. It is clear that the BPSSVM is potent in predicting the interactive modes between antibiotics and DNAs.
Co-reporter:Xiu Hui Liu, Kai Zhang, Cun Wu Dong, Shao Hua Zhang, Yue hua He, Xiao Yan Wang and Xiao Quan Lu
The Journal of Physical Chemistry C 2009 Volume 113(Issue 36) pp:16015-16020
Publication Date(Web):August 14, 2009
DOI:10.1021/jp901238j
A current oscillatory phenomenon was investigated systematically at the liquid/liquid interface with a three-electrode potentiostat in combination with cyclic voltammetry. We have focused our attention on the study of the electrostatic interaction between charged particles at the W/DCE interface in this paper. The experimental results demonstrate that the oscillation is caused by the specific adsorption of ion pairs at the liquid/liquid interface between Fe(CN)64− in the aqueous phase and TBA+ in the organic phase. A specific adsorption of ion pair model based on an oscillatory phenomenon is proposed for the first time, which is significant for us to understand the structure of the L/L interface better and to explain the properties of the interesting nonlinear oscillation patterns. A spectrophotometric experiment was performed to evidence a strong attractive interaction between Fe(CN)64− and TBA+.
Co-reporter:Fupeng Zhi, Xiaoquan Lu, Jiandong Yang, Xiaoyan Wang, Hui Shang, Shaohua Zhang and Zhonghua Xue
The Journal of Physical Chemistry C 2009 Volume 113(Issue 30) pp:13166-13172
Publication Date(Web):July 1, 2009
DOI:10.1021/jp9003278
Self-assembled monolayers (SAMs) of thiol-derivatized tetraphenylporphyrin on gold are able to bind anions reversibly from aqueous solutions. Electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM) are employed to investigate the binding of anions by porphyrin SAMs and proved to be efficient and convenient techniques for detecting anions in aqueous solutions using the redox couple Fe(CN)63−/4− as reporter ion. SAMs of porphyrins are shown to selectively bind dihydrogenphosphate over various other anions, including Cl−, Br−, NO2−, or NO3−. Gold electrodes modified with porphyrins can detect H2PO4− even in the presence of a 10-fold excess of other anions studied.
Co-reporter:Qin Wang, Fupeng Zhi, Wenting Wang, Xinghua Xia, Xiuhui Liu, Fanfu Meng, Yanyan Song, Chen Yang and Xiaoquan Lu
The Journal of Physical Chemistry C 2009 Volume 113(Issue 21) pp:9359-9367
Publication Date(Web):2017-2-22
DOI:10.1021/jp803725x
Self-assembled monolayers (SAMs) of thiol-derivatized tetraphenylporphyrin (SH-TPP) and cobalt tetraphenylporphyrin (SH-CoTPP) have been prepared to examine the structure and direct electron transfer (ET) on a gold electrode in an aqueous solution. The cyclic voltammetry peaks of the porphyrin were obviously observed in aqueous solution. An interesting phenomenon was that direct ET cannot occur in phosphate-buffered solutions when a highly oriented and tightly packed monolayer is in existence, but the relatively low-density SH-TPP SAMs exhibited good electrochemical response. The electron transfer rate constants were obtained from the impedance spectra (Cole−Cole plot), upon application of different biasing potentials to the modified electrode. We propose a new kinetic model of the ET processes of SAMs of thiol-derivatized porphyrin and apply the density functional theory (DFT) to study the ET of porphyrin molecules on Au surfaces.
Co-reporter:Xiaoquan Lu, Huiqing Yuan, Guofang Zuo, Jiandong Yang
Thin Solid Films 2008 Volume 516(Issue 18) pp:6476-6482
Publication Date(Web):31 July 2008
DOI:10.1016/j.tsf.2008.02.036
Self-assembled monolayers (SAMs) of thiol-porphyrins with different alkyl chain length (abbreviated as H2TPPO(CH2)nSH, n = 3, 6, 9 and 12) on gold electrode have been studied by electrochemical impedance spectroscopy in electrolytes containing a one-electron redox couple. From the size and separation of pinholes on SAMs, both estimated the values of charge-transfer resistance and pore size model, we get the surface coverage (θ). The results demonstrate that the surface coverage of saturated porphyrin modified gold electrode is close to unity (> 99%). But on the SAMs, a large number of pinholes still exist and acting as the microelectrodes, with average pinhole radius of 4–6 μm and the separations are ten times greater than the pinhole size, of 40–70 μm. Moreover, long chain length thiol-porphyrin SAM shows high surface coverage, larger pinhole size and excellent blocking of electron-transfer reactions between the redox mediator and the gold substrate. We demonstrated the large pinhole size is due to the aggregation of mass individual “micro-holes”.
Co-reporter:Xiaoquan Lu, Qin Wang, Xiuhui Liu
Analytica Chimica Acta 2007 Volume 601(Issue 1) pp:10-25
Publication Date(Web):3 October 2007
DOI:10.1016/j.aca.2007.08.021
Scanning electrochemical microscopy (SECM) has been proven to be a valuable technique for the quantitative investigation and surface analysis of a wide range of processes that occur at interfaces. In particular, there is a great deal of interest in studying the kinetics of charge transfer characteristics at the solid/liquid and liquid/liquid interface. This overview outlines recent advances and applications of SECM to the investigation of charge transfer reactions at the solid/liquid interface and liquid/liquid interface.
Co-reporter:Xiaoquan Lu;Yan Zhang;Min Zhang;Yina Chen
Journal of Solid State Electrochemistry 2007 Volume 11( Issue 4) pp:496-504
Publication Date(Web):2007 April
DOI:10.1007/s10008-006-0186-z
We have studied the micropatterning and characterization of the organic monolayers using cyclic voltammetry (CV), scanning electrochemical microscopy (SECM), atom force microscopy, and AC impedance, and have determined the electrochemical parameters, i.e., the apparent reaction rate constant (Kf) and the coverage of the electrode surface (θ). CV and SECM experiments demonstrated that the surface of the modified electrode represents an insulating substrate for ferricyanide. Using the high sensitivity of the electron transfer of ferricyanide to the modification of the gold surface with DNA, we selected this reaction as a probe to study the different modification stages at this modified electrode. SECM images obtained from bare, partially modified, and totally modified electrodes showed very good resolution with different topographies or null according to the extent of modification. Based on a comparison with the results of the experiments, a reasonable agreement can be obtained, which means a conjunction of these techniques.
Co-reporter:Yan Zhang;Xiaoquan Lu;Tianlu Liao;Yina Cheng
Journal of Solid State Electrochemistry 2007 Volume 11( Issue 9) pp:1303-1312
Publication Date(Web):2007 September
DOI:10.1007/s10008-007-0291-7
The interaction of 5-[p-(mercaptopropyloxy)-phenyl]-10, 15, 20-triphenylporphyrin (H2MPTPP) and its metalloporphyrin (Co, Ni-MPTPP) with calf thymus deoxyribonucleic acid (DNA) has been studied on gold electrode modified by thiol-porphyrin self-assembled monolayer (SAM). The mode and characteristics of their interaction with DNA have been studied by cyclic voltammetry, scanning electrochemical microscope (SECM), and alternating current (AC) impedance. Some electrochemical parameters have been determined, i.e., apparent heterogeneous reaction rate constant (keff from SECM and kf from AC impedance) and the hindrance (B) of electrode. K3[Fe(CN)6] was used as probe to obtain some electrochemical information of electrode interface. SECM images obtained from interface on SAM interacted with DNA showed very good resolution with different topography. Based on a comparison with the results from experiments, a reasonable agreement between SECM and AC impedance can be obtained, which means a conjunction of them. It is proposed to be electrostatic interaction of H2MPTPP, Co-MPTPP and Ni-MPTPP with DNA, and the attractive force between porphyrins and DNA follows the order Ni-MPTPP > Co-MPTPP > H2MPTPP.
Co-reporter:Xiaoquan Lu, Lan Wang, Hongde Liu, Rui Wang, Jing Chen
Talanta 2007 Volume 73(Issue 3) pp:444-450
Publication Date(Web):30 September 2007
DOI:10.1016/j.talanta.2007.04.006
In this paper, 24 parameters (descriptors) that can influence the interaction of selected antibiotic compound (antibiotics) and DNA have been investigated. Principal components analysis (PCA) and hierarchical cluster analysis (HCA) were employed in order to reduce dimensionality and investigate which subset of variables could be more effective for classifying the antibiotics according to their binding mode with DNA. Results of the PCA and HCA study showed that there are 12 descriptors closely related to the interaction. Based on these descriptors, multiple linear regression (MLR) and artificial neutral network (ANN) allowed us to propose three models which can predict binding constant and binding mode. For the prediction of binding constant, the minimal relative error is only 0.17% (MLR) and 0.72% (ANN); for the prediction of binding mode (ANN), five test molecules are all consistent with experimental results.
Co-reporter:Xiaoquan Lu, Hairui Zhang, Lina Hu, Cunyuan Zhao, Liming Zhang, Xiuhui Liu
Electrochemistry Communications 2006 Volume 8(Issue 6) pp:1027-1034
Publication Date(Web):June 2006
DOI:10.1016/j.elecom.2006.04.007
Scanning electrochemical microscopy (SECM) technology has been used to investigate the kinetics of heterogeneous electron transfer (ET) as a function of driving force at the interface between two immiscible electrolyte solutions (ITIES). The ET between metalloporphyrin species containing different substitutes in nitrobenzene and other redox species in the aqueous phase was studied and the rate constants were also extracted from the dependence of the steady-state current at a micrometer-sized tip electrode on the distance between the tip and the phase boundary when compared with the theoretical working curves. Corresponding to the various metalloporphyrin substitutes, SECM was demonstrated to be a useful means to study the effect of molecular structure on the kinetics of heterogeneous ET.
Co-reporter:Xiaoqiang Wang;Xiaoquan Lu;Minrui Li;Xiuhui Liu;Guofang Zuo;Yan Zhang;Limin Zhang
ChemPhysChem 2006 Volume 7(Issue 4) pp:854-862
Publication Date(Web):6 MAR 2006
DOI:10.1002/cphc.200500492
Herein, the scanning electrochemical microscopy (SECM) approach is applied to study the formation of thiol-porphyrin self-assembled monolayer (SAMs). Using cyclic voltammetry (CV), the formation process is characterized adopting different probe molecules. The observed phenomena indicate that the formation process is affected by solution properties and the molecular structure of the probe molecules. In K3Fe(CN)6 , the SAMs show a strong electron-transfer (ET) blocking effect on a pure porphyrin-modified electrode. However, addition of metal ions to the porphyrin molecules leads to ET. A consistent tendency is observed throughout the modification process using CV and SECM methods. Furthermore, keff values, the apparent heterogeneous rate constants, obtained for different modification periods affirm the validity of these results. SECM images are used to collect surface information in the course of the modification process when the substrate potential is 0.5 V versus Ag/AgCl. The effect of the substrate potential indicates that the oxidation of the porphyrin molecules is supported by more positive potentials because of the similar bimolecular reaction of the porphyrin ring with positive charge and the probe molecules with negative charge.
Co-reporter:Xiaoquan Lu;Rui Wang;Lan Wang;Jing Chen;Hongde Liu
Journal of Chemometrics 2005 Volume 19(Issue 11‐12) pp:648-656
Publication Date(Web):25 SEP 2006
DOI:10.1002/cem.973
In this paper, a named oscillation frequency spectrum (OFS) was developed for the frequency analysis of oscillating signal. Various complexing oscillating chemical reactions, which have been widely applied to analytical determination, were examined. The OFS extracted frequency information of these systems successfully and distinguished their respective frequency characteristics clearly. The details were such that the Belousov-Zhabotinskii (B-Z) system had three frequency peaks and the Cu(II)-catalyzed system had two. Every periodic signal had a special OFS. Even if the frequency values of two different signals were identical, their OFS figures were distinct. The OFS realized the extraction and calculation for the multifrequency characteristic of oscillating chemical system accurately. It followed that OFS could be used to analyze the frequency of periodic signal with accuracy and was suitable for many areas. Copyright © 2006 John Wiley & Sons, Ltd.
Co-reporter:Xiaoquan Lu, Baoqiang Lv, Zhonghua Xue, Minrui Li, Limin Zhang, Jingwan Kang
Thin Solid Films 2005 Volume 488(1–2) pp:230-235
Publication Date(Web):22 September 2005
DOI:10.1016/j.tsf.2005.04.116
A novel thiol-derivative porphyrin (5-[p-(mercaptopropyloxy)-phenyl]-10,15,20-triphenylporphine shortly as H2MPTPP) and its cobalt(II) complex (MPTPPCo(II) ) have been successfully immobilized on gold surface by self-assembly technique. The surface coverages (Γ) of MPTPPCo(II) was calculated to be 4.86 × 10− 11 mol/cm2 by investigating the reductive desorption of S–Au which demonstrated that the monolayer was not packed well and had many interval pinholes. The gold electrodes modified with MPTPPCo(II) and MPTPPCo(II) + thiolglycolic acid show good activity to the two-electron catalytic reduction of O2 to H2O2. Nanoscopic structures gained by atomic force microscopy (AFM) not only provided further evidence for the successful formation and immobilization of such monolayers, but also elucidated the potential reasons for the electrocatalytic activity of such monolayers to dissolved oxygen, which was proved to be very interesting and significant that the mixed monolayer could enhance the electroreduction and proceed more readily for the electroreduction of O2.
Co-reporter:Xiaoquan Lu, Jun Jin, Jingwan Kang, Baoqiang Lv, Hongde Liu, Zaixin Geng
Materials Chemistry and Physics 2003 Volume 77(Issue 3) pp:952-957
Publication Date(Web):30 January 2003
DOI:10.1016/S0254-0584(02)00221-3
A gold electrode modified by 5-{[4-(4-mercapto)phenylmethoxy]phenyl}-10,15,20-tris(phenyl)porphyrin cobalt(II) (MPPTPCo(II)) has been prepared. The properties of the modified electrode were investigated by scanning electronic microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) as well as electrochemical methods. The MPPTPCo(II)-SAM (SAM: self-assembled monolayer) modified electrode could successfully be used for the electrocatalytic oxidation of ascorbic acid (AA). The catalytic currents increased linearly with AA concentration in the range of 1.2×10−8–3.9×10−5 mol l−1 with the correlation coefficient of 0.9944. The detection limit was 2.6×10−9 mol l−1 with 10 min accumulation.
Co-reporter:Xiaoquan Lu, Zhihua Wang, Zaixin Geng, Jingwan Kang, Jinzhang Gao
Talanta 2000 Volume 52(Issue 3) pp:411-416
Publication Date(Web):30 June 2000
DOI:10.1016/S0039-9140(00)00392-1
A differential pulse anodic stripping voltammetry was developed for the sensitive and selective determination of Co(II) at 2,4,6-tri(3,5-dimethylpyrazoyl)-1,3,5-triazine modified carbon paste electrode in 0.1 mol l−1 NH4Cl solution (pH 4.95). The oxidation peak of Co(II) was observed at 0.03 V(vs. Ag/AgCl) by scanning the potential in a positive direction. The analysis procedure consisted of an open circuit accumulation step in stirred sample solution. This was followed by medium exchange to a clean solution and subsequently an anodic potential scan was effect to obtain the voltammetric peak. The current was proportional to the concentration of the Co(II) ion in a range of 1×10−8–1×10−6 mol l−1 for 3 min accumulation and in the range of 1×10−9–1×10−8 mol l−1 for 5 min accumulation; most of metal ions do not interfere with the determination. The developed method was applied to Co(II) determination in potable water.
Co-reporter:Zhonghua xue, Nan He, Honghong Rao, Chenxian Hu, Xiaofen Wang, Hui Wang, Xiuhui Liu, Xiaoquan Lu
Applied Surface Science (28 February 2017) Volume 396() pp:515-522
Publication Date(Web):28 February 2017
DOI:10.1016/j.apsusc.2016.10.185
Co-reporter:Zhonghua Xue, Hui Wang, Honghong Rao, Nan He, Xiaofen Wang, Xiuhui Liu, Xiaoquan Lu
Talanta (15 May 2017) Volume 167() pp:
Publication Date(Web):15 May 2017
DOI:10.1016/j.talanta.2017.03.009
•A simple yet effective amperometric indicator displacement assay for electrochemical inactive sarcosine was firstly explored.•A simple Ru(NH3)63+ and a natural organic NQS molecule was respectively proposed as the indicator and receptor.•An amperometric indicator displacement assay demonstrates high selectivity and excellent sensitivity toward sarcosine.Indicator displacement assay plays a fundamental role in the development of chemosensors. We explored here an ingenious yet effective strategy for amperometric assay of electrochemically inactive sarcosine based on an indicator displacement principle, in which 1,2-naphthoquinone-4-sulphonic acid sodium salt (NQS) was proposed as the receptor and the electroactive Ru(NH3)63+ cations used as an indicator. Due to the stronger binding affinity of the NQS toward sarcosine than toward Ru(NH3)63+, the developed amperometric indicator displacement assay (A-IDA) exhibits high selectivity and excellent sensitivity toward sarcosine determination as well as with a lower detection limit (30.00 nM, S/N =3).
Co-reporter:Samrat Devaramani, Mahgoub Ibrahim Shinger, Xiaofang Ma, Meng Yao, Shouting Zhang, Dongdong Qin and Xiaoquan Lu
Physical Chemistry Chemical Physics 2017 - vol. 19(Issue 28) pp:NaN18242-18242
Publication Date(Web):2017/07/06
DOI:10.1039/C7CP02815F
J- and H-aggregates of zinc tetraphenylporphyrin (ZnTPP) on carbon nanotube films (CNTFs) were prepared using the mixed solvent method. This resulted in completely different structures, such as the four-leaf clover and flower, on the CNTF, which were observed by recording SEM images. Characteristic changes in the electronic spectra of the ZnTPP monomer appeared when it underwent J- and H-aggregation. The measured photocurrent significantly varied for the same molecule when it was aggregated in two different ways on ITO and ITO/CNTF. The electron recombination resistance of the two aggregates, which was investigated using electrochemical impedance spectroscopy, was also different. The photocatalytic efficiency of the J- and H-aggregates was examined by performing methylene blue dye decoloration studies. In addition, a scanning electrochemical microscope was used to investigate the photoinduced charge transfer kinetics of the J- and H-aggregates at the electrode/electrolyte interface as a fresh attempt. The heterogeneous charge transfer constants for the J- and H-aggregates in the presence of light at varied intensities were calculated. Thereby, striking differences in the photophysical, photocatalytic, and photoelectrochemical properties of the J- and H-aggregates were visualized throughout our studies.
Co-reporter:Cai-He Wang, Dong-Dong Qin, Duo-Liang Shan, Jing Gu, Yong Yan, Jing Chen, Qiu-Hong Wang, Cai-Hua He, Yang Li, Jing-Jing Quan and Xiao-Quan Lu
Physical Chemistry Chemical Physics 2017 - vol. 19(Issue 6) pp:NaN4515-4515
Publication Date(Web):2017/01/10
DOI:10.1039/C6CP08066A
Graphitic carbon nitride (g-C3N4) has been widely studied as a metal-free photocatalyst, leading to some excellent results; however, the rapid recombination of photogenerated charge carriers substantially limits its performance. Here, we establish two types of g-C3N4-based heterojunction (type II and nonmediator assisted Z-scheme) photoanodes on a transparent conducting substrate via coupling with rod-like and nanoparticulate WO3, respectively. In these composites, g-C3N4 film grown by electrophoretic deposition of exfoliated g-C3N4 serves as the host or guest material. The optimized type II WO3/g-C3N4 composite exhibits an enhanced photocurrent of 0.82 mA cm−2 at 1.23 V vs. RHE and an incident photo-to-current conversion efficiency (IPCE) of 33% as compared with pure WO3 nanorods (0.22 mA cm−2 for photocurrent and 15% for IPCE). Relative to pure g-C3N4 film (with a photocurrent of several microampere and an IPCE of 2%), a largely improved photocurrent of 0.22 mA cm−2 and an IPCE of 20% were acquired for the Z-scheme g-C3N4/WO3 composite. The enhancement can be attributed to accelerated charge separation in the heterointerface because of the suitably aligned band gap between WO3 and g-C3N4, as confirmed by optical spectroscopy and ultraviolet photoelectron spectroscopy (UPS) analysis. The photocatalytic process and mechanism of the g-C3N4-based heterojunctions are proposed herein, which potentially explain the origin of the enhanced photoelectrochemical performance. This achievement and the fundamental information supplied here indicate the importance of rationally designing heterojunction photoelectrodes to improve the performance of semiconductors. This is particularly important for materials such as pure g-C3N4 and WO3, as their photoactivities are strongly restricted by high recombination rates.
Co-reporter:Jinfeng Wang, Jianxiao Gong, Yansong Xiong, Jiandong Yang, Yan Gao, Yaling Liu, Xiaoquan Lu and Zhiyong Tang
Chemical Communications 2011 - vol. 47(Issue 24) pp:NaN6896-6896
Publication Date(Web):2011/05/20
DOI:10.1039/C1CC11784J
We systematically explore the shape-dependent catalytic activities of Au nanocrystals toward glucose oxidation in alkaline electrolytes, which is strongly dependent on the shape of the Au nanocrystals. The {100}-bounded cubic Au nanocrystals are significantly more active than the {110}-bounded rhombic dodecahedral and {111}-bounded octahedral Au nanocrystals.
Co-reporter:Wenting Wang, Duoliang Shan, Yong Yang, Chunming Wang, Yaqi Hu and Xiaoquan Lu
Chemical Communications 2011 - vol. 47(Issue 24) pp:NaN6977-6977
Publication Date(Web):2011/05/23
DOI:10.1039/C1CC10842E
A new scanning electrochemical microscopy (SECM) model provided a two-dimensional quantitative analysis on a heterogeneous electron transport (ET) process of a functionalized porpyrin by photoinduced ET at the ITO/liquid interface. The basic features of oxidized porphyrin under light source were recorded by feedback approach curves within the framework of the bimolecular ET mechanisms.
Co-reporter:Xiaoquan Lu, Hetong Qi, Xuefeng Zhang, Zhonghua Xue, Jun Jin, Xibing Zhou and Xiuhui Liu
Chemical Communications 2011 - vol. 47(Issue 46) pp:NaN12496-12496
Publication Date(Web):2011/10/25
DOI:10.1039/C1CC15697G
A facile carbon radical reaction procedure and a chemical reduction method were proposed to synthesize Ag nanoparticles on functionalized graphene with uniform, high dispersion and excellent stability. The resultant material showed excellent electrocatalytic activity to nitroaromatic compounds and high sensitivity to the detection of nitroaromatic compounds.
![Methanaminium,N-[4-[[4-(dimethylamino)phenyl]phenylmethylene]-2,5-cyclohexadien-1-ylidene]-N-methyl-](http://img.cochemist.com/ccimg/10400/10309-95-2.png)
![Methanaminium,N-[4-[[4-(dimethylamino)phenyl]phenylmethylene]-2,5-cyclohexadien-1-ylidene]-N-methyl-](http://img.cochemist.com/ccimg/10400/10309-95-2_b.png)
![Zinc, [5,10,15,20-tetraphenyl-21H,23H-porphinato(2-)-κN21,κN22,κN23,κN24]-, (SP-4-1)-](/data/chemimg/478800/14074-80-7.png)
![Zinc, [5,10,15,20-tetraphenyl-21H,23H-porphinato(2-)-κN21,κN22,κN23,κN24]-, (SP-4-1)-](/data/chemimg/478800/14074-80-7_b.png)
