Co-reporter:Dong Liu, Leimiao Lin, Qiaofen Chen, Hongzhi Zhou, and Jianmin Wu
ACS Sensors - New in 2016 October 27, 2017 Volume 2(Issue 10) pp:1491-1491
Publication Date(Web):September 11, 2017
DOI:10.1021/acssensors.7b00459
Silicon nanowires/TiO2 (SiNWs/TiO2) array with core–shell nanostructure was created by sol–gel and drop-casting methods. The hybrid material displayed excellent sensing performance for CH4 detection at room temperature. The chemiresistor sensor has a linear response toward CH4 gas in the 30–120 ppm range with a detection limit of 20 ppm, which is well below most CH4 sensors reported before. The enhanced gas sensing performance at room temperature was attributed to the creation of heterojunctions that form a depletion layer at the interface of SiNWs and TiO2 layer. Adsorption of oxygen and corresponding gas analyte on TiO2 layer could induce the change of depletion layer thickness and consequently the width of the SiNWs conductive channel, leading to a sensitive conductive response toward gas analyte. Compared to conventional metal oxide gas sensors, the room temperature gas sensors constructed from SiNWs/TiO2 do not need an additional heating device and work at power at the μW level. The low power consumption feature is of great importance for sensing devices, if they are widely deployed and connected to the Internet of Things. The innovation of room temperature sensing materials may push forward the integration of gas sensing element with wireless device.Keywords: core−shell nanostructure; heterojunction; methane sensing; silicon nanowires; titanium dioxide;
Co-reporter:Xisheng Chen, Fangjie Wo, Yao Jin, Jie Tan, Yan Lai, and Jianmin Wu
ACS Nano August 22, 2017 Volume 11(Issue 8) pp:7938-7938
Publication Date(Web):July 12, 2017
DOI:10.1021/acsnano.7b02471
Wound monitoring and curing is of great importance in biomedical research. This work created a smart bandage that can simultaneously monitor and inhibit wound infection. The main components of the smart bandage are luminescent porous silicon (LuPSi) particles loaded with ciprofloxacin (CIP). This dual luminescent system can undergo accelerated fluorescent color change from red to blue upon the stimulation of reactive oxygen species (ROS) and elevated pH, which are main biomarkers in the infected wound. The mechanism behind the chemical-triggered fluorescent color change was studied in detail. In vitro experiment showed that the ratiometric fluorescent intensity (IRed/IBlue) of CIP-LuPSi particles decreased from 10 to 0.03 at pH 7.5 after 24 h, while the value deceased from 10 to 2.15 at pH 7.0. Strong correlation can be also found between the IRed/IBlue value and ROS concentration ranging from 0.1 to 10 mM. In addition, the oxidation of LuPSi also simultaneously triggered the release of CIP molecules, which exhibited bacterial inhibition activity. Therefore, the ratiometric fluorescent intensity change at red and blue channels can indicate not only the wound infection status but also the release of antibiotics. In vivo test proved that the smart bandage could distinguish infected wounds from acute wounds, just relying on the naked eyes or a cell phone camera. On the basis of the Si nanotechnology established in this work, theranostic wound care will be realized in future.Keywords: luminescent porous silicon; ratiometric fluorescence; reactive oxygen species; smart bandage; wound monitoring;
Co-reporter:Xiao Li;Xiaoming Chen;Jie Tan;Xiao Liang;Jianmin Wu
Analyst (1876-Present) 2017 vol. 142(Issue 4) pp:586-590
Publication Date(Web):2017/02/13
DOI:10.1039/C6AN02165D
Interest in using mesoporous materials for peptidomic research has increased recently. The present study reports a new type of matrix assisted laser desorption/ionization (MALDI) plate derived from electrochemically etched porous silicon (PSi) whose surface was modified with palladium nanoparticles (PdNPs). Owing to the well-tailored pore size and the molecular filtration effect of the PSi, peptides in serum samples can be selectively captured and enriched in the pore channel, thereby eliminating the interference from large proteins in subsequent MALDI-MS detection. On the other hand, the PdNPs with localized surface plasmon resonance (LSPR) effect can help to enhance the efficiency of energy absorption in the UV region. Meanwhile, the charge separation effect between the PSi semiconductor and PdNPs also can be applied to promote the accumulation of positive charges on PdNPs, resulting in an improvement in laser desorption/ionization (LDI) efficiency under positive linear detection mode. The interplay among these unique properties of PSi and PdNPs can synergistically increase the overall sensitivity in serum peptide detection. Using this technology, serum sample can be directly detected on the PSi-PdNPs chip without complicated pretreatment process. Therefore, a high fidelity serum peptide fingerprint can be acquired in a high throughput way. With the assistance of statistical analysis, colorectal cancer patients and healthy people can be accurately distinguished based on the serum peptide fingerprints.
Co-reporter:Jie Tan, Xiaomin Chen, Guansheng Du, Qiaohui Luo, Xiao Li, Yaqing Liu, Xiao Liang and Jianmin Wu
Chemical Communications 2016 vol. 52(Issue 17) pp:3490-3493
Publication Date(Web):18 Jan 2016
DOI:10.1039/C5CC09419D
A serum peptide profile contains important bio-information, which may help disease classification. The motivation of this study is to take advantage of porous silicon microparticles with multiple surface chemistries to reduce the loss of peptide information and simplify the sample pretreatment. We developed a multi-dimensional on-particle MALDI-TOF technology to acquire high fidelity and cross-reactive molecular fingerprints for mining disease information. The peptide fingerprint of serum samples from colorectal cancer patients, liver cancer patients and healthy volunteers were measured with this technology. The featured mass spectral peaks can successfully discriminate and predict the multi-category disease. Data visualization for future clinical application was also demonstrated.
Co-reporter:X. Zhu, D. Liu, Q. Chen, L. Lin, S. Jiang, H. Zhou, J. Zhao and J. Wu
Chemical Communications 2016 vol. 52(Issue 14) pp:3042-3045
Publication Date(Web):12 Jan 2016
DOI:10.1039/C5CC08652C
A flexible graphene sensor array has been fabricated by in situ reduction of a graphene oxide (GO) array patterned on a paper chip. To achieve cross-reactive sensing and gas discrimination ability, the surface of each reduced GO (rGO) spot was modified with different types of ionic liquids (ILs), which could significantly alter the semiconductor properties and consequently the gas sensing behaviour of the paper-supported rGO sensor.
Co-reporter:Yanyan Tang, Zhen Li, Qiaohui Luo, Jingqing Liu, Jianmin Wu
Biosensors and Bioelectronics 2016 Volume 79() pp:715-720
Publication Date(Web):15 May 2016
DOI:10.1016/j.bios.2015.12.109
Bacteria detection plays an important role in the guarantee of food and water safety. This work proposed a new sensing strategy for the rapid detection of bacteria based on its blockage effect on nanopore array, which was prepared from electrochemically etched silicon. With the assistance of microfluidic technology, the nanopore array attached with Escherichia coli antibody can selectively and rapidly capture E. coli bacteria, resulting in the decrease of pore accessibility. The signal of pore blockage can be measured by in-direct Fourier Transformed Reflectometric Interference Spectroscopy (FT-RIS). The pore blockage signal has a linear relationship with the logarithm of bacterial density in aqueous sample within the range from 103 to 107 cfu ml−1. Due to the specific interaction between the antibody and target bacteria, only the E. coli sample displayed significant pore blockage effect, whereas the non-target bacteria, Nox and P17, almost did not show any pore blockage effect. The strategy established in this work might be pervasively applied in the rapid detection of target bacteria and cell in a label-free manner.
Co-reporter:Jie Tan, Xiao Li, Guansheng Du, Aiwu Pan and Jianmin Wu
Chemical Communications 2014 vol. 50(Issue 18) pp:2334-2337
Publication Date(Web):09 Jan 2014
DOI:10.1039/C3CC49094G
Serum peptides are becoming a rich source of disease biomarkers, therefore, preserving serum peptide information after sample collection is of great importance. This work demonstrates that nanoporous silicon microparticles can be successfully applied in the storage of peptide information.
Co-reporter:Zhen Li, Yanyan Tang, Ling Zhang and Jianmin Wu
Lab on a Chip 2014 vol. 14(Issue 2) pp:333-341
Publication Date(Web):07 Oct 2013
DOI:10.1039/C3LC50937K
A label-free optical sensor was constructed by integrating pH sensing material and supported phospholipid bilayers (SPBs) in a microfluidic chip. The pH sensing material was composed of a double layer structure consisting of chitosan hydrogel and electrochemically etched porous silicon. The pH change in the microchip could induce a reversible swelling of the chitosan hydrogel layer and consequently caused a shift in effective optical thickness (EOT) of the double layer, which could be observed by Fourier transformed reflectometric interference spectroscopy (FT-RIS). After phospholipid bilayers (PLBs) were self-assembled on the sensing layer, the EOT almost remained constant during the cycling of pH from 7.4 to 6.2, indicating the blockage of H+ translocation by the PLBs. For studying the behavior of ion channel protein, gramicidin A, a typical ion channel protein, was inserted in the SPBs for mimicking the ion transportation function of cell membrane. Due to the H+ transportation capability of gramicidin A, the optical response to pH change could partially recover. In the presence of Ca2+, the pore of the ion channel protein was blocked, causing a significant decrease in the EOT response upon pH change. The bio-functionalized microfluidic sensor fabricated in this work will provide a reliable platform for studying the function of ion channel protein, which is an important class of drug targets.
Co-reporter:Xiao Li, Jie Tan, Jiekai Yu, Jiandong Feng, Aiwu Pan, Shu Zheng, Jianmin Wu
Analytica Chimica Acta 2014 Volume 849() pp:27-35
Publication Date(Web):7 November 2014
DOI:10.1016/j.aca.2014.08.028
•Porous silicon–gold nanoparticle (PSi–GNP) hybrid was used as new type of MALDI chip.•The PSi–GNP can greatly enhance MS signal intensity in serum peptide detection.•The plasmon and charge transfer effect of PSi–GNP lead to the MS signal enhancement.•Interference from large proteins can be eliminated with the PSi–GNP chip.•High quality serum peptide fingerprint can be acquired with the chip.Small peptides in serum are potential biomarkers for the diagnosis of cancer and other diseases. The identification of peptide biomarkers in human plasma/serum has become an area of high interest in medical research. However, the direct analysis of peptides in serum samples using mass spectrometry is challenging due to the low concentration of peptides and the high abundance of high-molecular-weight proteins in serum, the latter of which causes severe signal suppression. Herein, we reported that porous semiconductor-noble metal hybrid nanostructures can both eliminate the interference from large proteins in serum samples and significantly enhance the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) yields of peptides captured on the nanostructure. Serum peptide fingerprints with high fidelity can be acquired rapidly, and successful discrimination of colorectal cancer patients based on peptide fingerprints is demonstrated.
Co-reporter:Sai Ma, Yanyan Tang, Jingqing Liu, Jianmin Wu
Talanta 2014 Volume 120() pp:135-140
Publication Date(Web):March 2014
DOI:10.1016/j.talanta.2013.12.007
Co-reporter:Jie Tan;Linru Xu;Tong Li; Bin Su ; Jianmin Wu
Angewandte Chemie International Edition 2014 Volume 53( Issue 37) pp:9822-9826
Publication Date(Web):
DOI:10.1002/anie.201404948
Abstract
The electrochemiluminescence (ECL) of porous silicon (pSi) has attracted great interest for its potential application in display technology and chemical sensors. In this study, we found that pSi with a different surface chemistry displayed an apparently different dynamic ECL process. An image-contrast technology was established on the basis of the intrinsic mechanism of the ECL dynamic process. As a proof of principle, the visualization of latent fingerprints (LFPs) and in situ detection of TNT in fingerprints was demonstrated by using the ECL-based image-contrast technology.
Co-reporter:Jie Tan;Linru Xu;Tong Li; Bin Su ; Jianmin Wu
Angewandte Chemie 2014 Volume 126( Issue 37) pp:9980-9984
Publication Date(Web):
DOI:10.1002/ange.201404948
Abstract
The electrochemiluminescence (ECL) of porous silicon (pSi) has attracted great interest for its potential application in display technology and chemical sensors. In this study, we found that pSi with a different surface chemistry displayed an apparently different dynamic ECL process. An image-contrast technology was established on the basis of the intrinsic mechanism of the ECL dynamic process. As a proof of principle, the visualization of latent fingerprints (LFPs) and in situ detection of TNT in fingerprints was demonstrated by using the ECL-based image-contrast technology.
Co-reporter:Yanyan Tang, Li Zhen, Jingqing Liu, and Jianmin Wu
Analytical Chemistry 2013 Volume 85(Issue 5) pp:2787
Publication Date(Web):January 29, 2013
DOI:10.1021/ac303282j
For appropriate selection of antibiotics in the treatment of pathogen infection, rapid antibiotic susceptibility testing (AST) is urgently needed in clinical practice. This study reports the utilization of a microfluidic pH sensor for monitoring bacterial growth rate in culture media spiked with different kinds of antibiotics. The microfluidic pH sensor was fabricated by integration of pH-sensitive chitosan hydrogel with poly(dimethylsiloxane) (PDMS) microfluidic channels. For facilitating the reflectometric interference spectroscopic measurements, the chitosan hydrogel was coated on an electrochemically etched porous silicon chip, which was used as the substrate of the microfluidic channel. Real-time observation of the pH change in the microchannel can be realized by Fourier transform reflectometric interference spectroscopy (FT-RIFS), in which the effective optical thickness (EOT) was selected as the optical signal for indicating the reversible swelling process of chitosan hydrogel stimulated by pH change. With this microfluidic pH sensor, we demonstrate that confinement of bacterial cells in a nanoliter size channel allows rapid accumulation of metabolic products and eliminates the need for long-time preincubation, thus reducing the whole detection time. On the basis of this technology, the whole bacterial growth curve can be obtained in less than 2 h, and consequently rapid AST can be realized. Compared with conventional methods, the AST data acquired from the bacterial growth curve can provide more detailed information for studying the antimicrobial behavior of antibiotics during different stages. Furthermore, the new technology also provides a convenient method for rapid minimal inhibition concentration (MIC) determination of individual antibiotics or the combinations of antibiotics against human pathogens that will find application in clinical and point-of-care medicine.
Co-reporter:Yinfen Hu;Man Zhang;Changlun Tong;Jianmin Wu;Weiping Liu
Journal of Separation Science 2013 Volume 36( Issue 20) pp:3321-3329
Publication Date(Web):
DOI:10.1002/jssc.201300663
There have been great concerns about the persistence of steroid hormones in surface water. Since the concentrations of these compounds in water samples are usually at a trace level, the efficient enrichment of steroid hormones is vital for further analysis. In this work, a porous and hydrophobic polymer was synthesized and characterized. The composition of solvent used as porogen in the synthetic process was shown to have an effect on the morphology of the polymer, which was successfully used as an SPE sorbent for simultaneously enriching steroid hormones in surface water samples. The recoveries of the steroid hormones on the custom-made polymer ranged from 93.4 to 106.2%, whereas those on commercialized ENVI-18, LC-18, and Oasis HLB ranged from 54.8 to 104.9, 66 to 93.6, and 77.2 to 106%, respectively. Five types of steroid hormones were simultaneously measured using HPLC–UV after they were enriched by the custom-made sorbent. Based on these findings, the SPE–HPLC method was developed. The LODs of this method for estriol, estradiol, estrone, androstenedione, progesterone were 0.07, 0.43, 0.61, 0.27, and 0.42 μg/L, respectively, while precision and reproducibility RSDs were <6.40 and 7.49%, respectively.
Co-reporter:Jie Tan;Wei-Jie Zhao;Jie-Kai Yu;Sai Ma;Michael J. Sailor;Jian-Min Wu
Advanced Healthcare Materials 2012 Volume 1( Issue 6) pp:742-750
Publication Date(Web):
DOI:10.1002/adhm.201200161
Abstract
Mining the disease information contained in the low-molecular-weight range of a proteomic profile is becoming of increasing interest in cancer research. This work evaluates the ability of nanoporous silicon microparticles (NPSMPs) to capture, enrich, protect, and detect low-molecular-weight peptides (LMWPs) sieved from a pool of highly abundant plasma proteins. The average pore size and porosity of NPSMPs are controlled by the electrochemical preparation conditions, and the critical parameters for admission or exclusion of protein with a definite molecular weight are determined by reflectometric-interference Fourier transform spectroscopy (RIFTS). Sodium dodecyl sulfate polyacrylamide-gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) analysis of the proteins captured by the NPSMPs show that the chemical nature of the NPSMPs surface and the solution pH also play vital roles in determining the affinity of NPSMPs for target analytes. It is found that carboxyl-terminated porous microparticles with a porosity of 26% (pore diameter around 9.0 nm) specifically fractionate, enrich and protect LMWPs sieved from either simulated samples or human serum samples. Moreover, NPSMPs containing captured peptides can be directly spotted onto a MALDI plate. When placed in a conventional MALDI matrix, laser irradiation of the particles results in the release of the target peptides confined in the nanopores, which are then ionized and detected in the MALDI experiment. As a proof-of-principle test case, mass spectra of NPSMPs prepared using serum from colorectal cancer patients and from control patients can be clearly distinguished by statistical analysis. The work demonstrates the utility of the method for discovery of biomarkers in the untapped LMWP fraction of human serum, which can be of significant value in the early diagnosis and management of diseases.
Co-reporter:Yunling Shang, Xiaobo Wang, Erchao Xu, Changlun Tong, Jianmin Wu
Analytica Chimica Acta 2011 Volume 685(Issue 1) pp:58-64
Publication Date(Web):24 January 2011
DOI:10.1016/j.aca.2010.11.008
An ammonia gas sensor chip was prepared by coating an electrochemically-etched porous Si rugate filter with a chitosan film that is crosslinked by glycidoxypropyltrimethoxysilane (GPTMS). The bromothylmol blue (BTB), a pH indicator, was loaded in the film as ammonia-sensing molecules. White light reflected from the porous Si has a narrow bandwidth spectrum with a peak at 610 nm. Monitoring reflective optical intensity at the peak position allows for direct, real-time observation of changes in the concentration of ammonia gas in air samples. The reflective optical intensity decreased linearly with increasing concentrations of ammonia gas over the range of 0–100 ppm. The lowest detection limit was 0.5 ppm for ammonia gas. At optimum conditions, the full response time of the ammonia gas sensor was less than 15 s. The sensor chip also exhibited a good long-term stability over 1 year. Therefore, the simple sensor design has potential application in miniaturized optical measurement for online ammonia gas detection.
Co-reporter:Yunling Shang;Haijuan Zhang;Xiaobo Wang ; Jianmin Wu
Chemistry - A European Journal 2011 Volume 17( Issue 48) pp:13400-13404
Publication Date(Web):
DOI:10.1002/chem.201101572
Co-reporter:Jiandong Feng, Weijie Zhao, Bin Su, Jianmin Wu
Biosensors and Bioelectronics 2011 30(1) pp: 21-27
Publication Date(Web):
DOI:10.1016/j.bios.2011.08.021
Co-reporter:Shanshan Qu, Xiaobo Wang, Changlun Tong, Jianmin Wu
Journal of Chromatography A 2010 Volume 1217(Issue 52) pp:8205-8211
Publication Date(Web):24 December 2010
DOI:10.1016/j.chroma.2010.10.097
A new molecularly imprinted polymer (MIP) targeting to quinolones (Qs) and tetracyclines (TCs) was synthesized using itaconic acid (ITA) and ciprofloxacin (CIP) as a functional monomer and template molecule, respectively. Factors affecting the overall performance of MIP were investigated, and the results showed that Fe3+ ion play a vital role in the formation of MIP with high molecular imprinting effect. Meanwhile, the chelating ability of monomer, species of template molecule, as well as the molar ratio of monomer and template also contribute to the performance of the obtained MIP. Cyclic voltammetry verified that, with the participation of Fe3+ ions, a ternary complex of ITA–Fe3+–CIP could be formed before polymerization. Compared with conventional MIP prepared from commonly used monomer, methacrylic acid (MAA), the new MIP show significantly enhanced molecular imprinting effect and higher capacity for specific adsorption of target compounds as revealed by static and dynamic binding experiments. The MIP was successfully used as solid-phase extraction (SPE) adsorbent for enriching a broad spectrum of antibiotics containing beta-diketone structure from surface water sample. HPLC detection showed that high recovery rate (78.6–113.6%) was found in these spiked antibiotics, whereas recovery rate for the non structurally related drugs, epinephrine (EP) and dopamine (DOPA), was very low (4.7–7.6%) on the MIP cartridges. The results demonstrate that the MIP prepared by the strategy proposed in this work, could specifically target to a series of structurally related antibiotics containing beta-diketone structure.
Co-reporter:Yunling Shang, Weijie Zhao, Erchao Xu, Changlun Tong, Jianmin Wu
Biosensors and Bioelectronics 2010 Volume 25(Issue 5) pp:1056-1063
Publication Date(Web):15 January 2010
DOI:10.1016/j.bios.2009.09.029
Post-column identification of target compounds in complex samples is one of the major tasks in drug screening and discovery. In this work, we demonstrated that double layer porous silicon (PSi) attached with affinity ligand could serve as a sensing element for post-column detection of target molecule by Fourier transformed reflectometric interference spectroscopy (FTRIFS), in which trypsin and its inhibitor were used as the model probe–target system. The double layer porous silicon was prepared by electrical etching with a current density of 500 mA/cm2, followed by 167 mA/cm2. Optical measurements indicated that trypsin could infiltrate into the outer porous layer (porosity 83.6%), but was excluded by the bottom layer (porosity 52%). The outer layer, attached with trypsin by standard amino-silane and glutaraldehyde chemistry, could specifically bind with the trypsin inhibitor, acting as a sample channel, while the bottom layer served as a reference signal channel. The binding event between the attached trypsin and trypsin inhibitor samples could be detected by FTRIFS in real-time through monitoring the optical thickness change of the porous silicon layer. The baseline drift caused by sample matrix variation could be effectively eliminated by a signal correction method. Optical signals had a linear relationship with the concentration of trypsin inhibitor in the range of 10–200 ng mL−1. The FTRIFS biosensor based on double layer porous silicon could be combined with a UV detector for screening the target molecule from complex component mixtures separated by a LC column. Using an LC–UV–FTRIFS system, a fraction containing a trypsin inhibitor could be separated from a soybean extract sample and identified in real-time.
Co-reporter:Changlun Tong, Xiajun Zhuo, Weiping Liu, Jianmin Wu
Talanta 2010 Volume 82(Issue 5) pp:1858-1863
Publication Date(Web):15 October 2010
DOI:10.1016/j.talanta.2010.07.082
A simple, rapid and sensitive synchronous fluorescence method is put forward for the determination of enrofloxacin (ENRO) in the pharmaceutical formulation and its residue in milk based on the yttrium (III)-perturbed luminescence. When Y3+ is added into the ENRO solution, the fluorescence of ENRO is significantly enhanced. The synchronous fluorescence technology is employed in the method to determine trace amount of ENRO residue in milks. The synchronous fluorescence intensity of the system is measured in a 1-cm quartz cell with excitation wavelength of 328 nm, Δλ = 80 nm. A good linear relationship between the fluorescence intensity and the ENRO concentration is obtained in the range of 1.0 × 10−9 to 2.0 × 10−6 mol L−1 (r2 = 0.9992). The limit of detection (LOD) of this method attains as low as 3.0 × 10−10 mol L−1 (S/N = 3). The selectivity of this method is also very good. Common metal ions, rare-earth ions and some pharmaceuticals, which are usually used together with ENRO, do not interfere with the determination of ENRO under the actual conditions. The proposed method can be applied to determine ENRO residue in milks, and limit of quantification (LOQ) determined in the spiked milk is estimated to be 2.8 × 10−8 mol L−1 (10 μg L−1). Moreover, this method can be used as a rapid screening for judging whether the ENRO residues in milks exceed Minimal Risk Levels (MRLs) or not. In addition, the mechanism of the fluorescence enhancement is also discussed in detail.
Co-reporter:Ai Wu Pan, Bei Bei Wu, Jian Min Wu
Chinese Chemical Letters 2009 Volume 20(Issue 1) pp:79-83
Publication Date(Web):January 2009
DOI:10.1016/j.cclet.2008.10.012
pH-responsive-chitosan nanoparticles for the control release of protein drug were prepared by combining two-step crosslinking method, in which chitosan was subsequently crosslinked by sodium tripolyphosphate (TPP) and glycidoxypropyltrimethoxysilane (GPTMS). Compared with TPP crosslinked chitosan particles, the two-step crosslinked nanoparticles were not only pH-responsive but also more stable in wide pH range. Fluorescein isothiocyanate (FITC) labeled anti-human-IgG antibody was used as a model protein drug for evaluating the control release profile of the nano-carrier. The amount of released antibody increased from 5.6% to 50% when the pH of solution shifted from 7.4 to 6.0. The results suggest the possible application of the nanoparticles as pH-responsive drug delivery materials.
Co-reporter:Haijuan Zhang, Leimiao Lin, Dong Liu, Qiaofen Chen, Jianmin Wu
Analytica Chimica Acta (8 February 2017) Volume 953() pp:
Publication Date(Web):8 February 2017
DOI:10.1016/j.aca.2016.11.053
•Ionic liquids confined in the pore channel of porous silicon (PSi) can form microdroplets on the PSi surface upon exposure to VOCs.•These VOC-stimulated microdroplets could scattered the light reflected from the PSi rugate filter, thereby producing an optical response to VOC.•The infiltrated ionic liquids can significantly improve the selectivity of the PSi sensor owing to the selective molecular interaction.•The ILs/PSi sensor array can generate a unique cross-reactive “fingerprint” in response to a specific type of VOC analyte.A photonic-nose for the detection and discrimination of volatile organic compounds (VOCs) was constructed. Each sensing element on the photonic sensor array was formed by infiltrating a specific type of ionic liquid (IL) into the pore channel of a patterned porous silicon (PSi) chip. Upon exposure to VOC, the density of IL dramatically decreased due to the nano-confinement effect. As a result, the IL located in pore channel expanded its volume and protrude out of the pore channel, leading to the formation of microdroplets on the PSi surface. These VOC-stimulated microdroplets could scatter the light reflected from the PSi rugate filter, thereby producing an optical response to VOC. The intensity of the optical response produced by IL/PSi sensor mainly depends on the size and shape of microdroplets, which is related to the concentration of VOC and the physi-chemical propertied of ILs. For ethanol vapor, the optical response has linear relationship with its relative vapor pressure within 0–60%. The LOD of the IL/PSi sensor for ethanol detection is calculated to be 1.3 ppm. It takes around 30 s to reach a full optical response, while the time for recovery is less than 1 min. In addition, the sensor displayed good stability and reproducibility. Owing to the different molecular interaction between IL and VOC, the ILs/PSi sensor array can generate a unique cross-reactive “fingerprint” in response to a specific type of VOC analyte. With the assistance of image technologies and principle components analysis (PCA), rapid discrimination of VOC analyte could be achieved based on the pattern recognition of photonic sensor array. The technology established in this work allows monitoring in-door air pollution in a visualized way.
Co-reporter:X. Zhu, D. Liu, Q. Chen, L. Lin, S. Jiang, H. Zhou, J. Zhao and J. Wu
Chemical Communications 2016 - vol. 52(Issue 14) pp:NaN3045-3045
Publication Date(Web):2016/01/12
DOI:10.1039/C5CC08652C
A flexible graphene sensor array has been fabricated by in situ reduction of a graphene oxide (GO) array patterned on a paper chip. To achieve cross-reactive sensing and gas discrimination ability, the surface of each reduced GO (rGO) spot was modified with different types of ionic liquids (ILs), which could significantly alter the semiconductor properties and consequently the gas sensing behaviour of the paper-supported rGO sensor.
Co-reporter:Jie Tan, Xiao Li, Guansheng Du, Aiwu Pan and Jianmin Wu
Chemical Communications 2014 - vol. 50(Issue 18) pp:NaN2337-2337
Publication Date(Web):2014/01/09
DOI:10.1039/C3CC49094G
Serum peptides are becoming a rich source of disease biomarkers, therefore, preserving serum peptide information after sample collection is of great importance. This work demonstrates that nanoporous silicon microparticles can be successfully applied in the storage of peptide information.
Co-reporter:Jie Tan, Xiaomin Chen, Guansheng Du, Qiaohui Luo, Xiao Li, Yaqing Liu, Xiao Liang and Jianmin Wu
Chemical Communications 2016 - vol. 52(Issue 17) pp:NaN3493-3493
Publication Date(Web):2016/01/18
DOI:10.1039/C5CC09419D
A serum peptide profile contains important bio-information, which may help disease classification. The motivation of this study is to take advantage of porous silicon microparticles with multiple surface chemistries to reduce the loss of peptide information and simplify the sample pretreatment. We developed a multi-dimensional on-particle MALDI-TOF technology to acquire high fidelity and cross-reactive molecular fingerprints for mining disease information. The peptide fingerprint of serum samples from colorectal cancer patients, liver cancer patients and healthy volunteers were measured with this technology. The featured mass spectral peaks can successfully discriminate and predict the multi-category disease. Data visualization for future clinical application was also demonstrated.
