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Now showing items 1 - 8 of 8

  • Portable glucose meter:trends in techniques and its potential application in analysis

    Zhang, Linan   Gu, Chunchuan   Ma, Huan   Zhu, Langlang   Wen, Jiajun   Xu, Hanxiao   Liu, Hongying   Li, Lihua  

    A blood glucose meter is an electronic medical device used for determining the concentration of glucose in blood. These meters have undergone five phases of development: washed blood glucose meters, wiped blood glucose meters, colorimetric blood glucose meters, electrochemical blood glucose meters, and micro, multiple site blood glucose meters. Thanks to their speed, portability, low cost, and easy operation, blood glucose meters have been widely available for use in clinical diagnosis. Recently, coupling of target recognition elements (antibody-antigen recognition, nucleic acid hybridization, enzyme recognition, and click chemistry) with signal transduction and amplification strategies (glucose-generating enzymes, nicotinamide adenine dinucleotide (NADH)-generating enzymes, encapsulated glucose, nanomaterials, and cyclic amplification of DNA) has allowed various targets to be determined via the relationship between the signal of the blood glucose meter and the concentration of targets. In this paper, a brief review of the development and mechanism of blood glucose meters is given first. Then, more details on the application of blood glucose meters in analysis are described, including biomedical analysis, food analysis, and environmental analysis. Finally, the prospect of future development of blood glucose meters is also discussed
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  • Quantum dots-based fluorescence resonance energy transfer biosensor for monitoring cell apoptosis.

    Gu, Chunchuan  

    The development of advanced methods for accurately monitoring cell apoptosis has extensive significance in the diagnostic and pharmaceutical fields. In this study, we developed a rapid, sensitive and selective approach for the detection of cell apoptosis by combining the site-specific recognition and cleavage of the DEVD-peptide with quantum dots (QDs)-based fluorescence resonance energy transfer (FRET). Firstly, biotin-peptide was conjugated on the surface of AuNPs to form AuNPs-pep through the formation of an Au-S bond. Then, AuNPs-pep-QDs nanoprobe was obtained through the connection between AuNPs-pep and QDs. FRET is on and the fluorescence of QDs is quenched at this point. The evidence of UV-vis spectra, transmission electron microscopy (TEM), and Fourier transform infrared (FT-IR) spectroscopy revealed that the connection was successful. Upon the addition of apoptosis cell lysis solution, peptide was cleaved by caspase-3, and AuNPs was dissociated from the QDs. At this time, FRET is off, and thus the QDs fluorescence was recovered. The experimental conditions were optimized in terms of ratio of peptide to AuNPs, buffer solution, and the temperature of conjugation and enzyme reaction. The biosensor was successfully applied to distinguishing apoptosis cells and normal cells within 2h. This study demonstrated that the biosensor could be utilized to evaluate anticancer drugs. Copyright =C2=A9 2017 John Wiley & Sons, Ltd.
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  • Copper(II)-coated Fe3O4 nanoparticles as an efficient enzyme mimic for colorimetric detection of hydrogen peroxide

    Liu, Hongying   Zhu, Langlang   Ma, Huan   Wen, Jiajun   Xu, Hanxiao   Qiu, Yubing   Zhang, Linan   Li, Lihua   Gu, Chunchuan  

    The authors describe the preparation of Cu(II)-coated Fe3O4) nanoparticles (NPs) that possess excellent peroxidase-like activity. The NPs were formed by chelation between Cu(II) ions and the oxygen functional groups of sodium ligninsulfonate. The morphology and structure of the NPs were characterized by scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The NPs have an average diameter of 220 nm. They are shown to be viable peroxidase mimics that can catalyze the oxidation of 3,3', 5,5'tetramethylbenzidine by hydrogen peroxide to produce a blue coloration. The findings were used to design a colorimetric assay that has a linear response in the 2.5 to 100 mu MH2O2 concentration range and a 0.2 mu M detection limit. The assay excels by its selectivity, high sensitivity, good selectivity, portability and cost efficiency.
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  • One-Pot Electrodeposition of NiS Nanoparticles as an Efficient Electrode for Nonenzymatic H2O2 and Glucose Sensors

    Huang, Zhiheng   Gu, Chunchuan   Wen, Jiajun   Zhu, Langlang   Zhang, Mingzhen   Liu, Hongying  

    In this paper, a new and one-pot electrodeposition method was expanded for the preparation of NiS nanoparticles-based electrochemical biosensor using metal-ion complexes as a precursor. Thioacetamide was used to control the production rate of NiS nanoparticles for the first time. The proposed electrochemical sensor was characterized by energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscope (FESEM), cyclic voltammograms (CV), and electrochemical impedance spectra (EIS). Experiment parameters were optimized. Under the optimized condition, the prepared NiS-based biosensor exhibited excellent electrocatalytic oxidation of H2O2 and glucose due to their small size. It provided fast and sensitive strategy for detecting H2O2 and glucose in the range of 1-5000 and 1-1000 mu M. The detection limit of 0.257 and 0.3 mu M was obtained for H2O2 and glucose. The mechanisms were also analyzed. The proposed biosensor exhibited excellent anti-interference and repeatability. Furthermore, it was applied in the actual sample analysis, such as human blood serum.
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  • Non-enzymatic hydrogen peroxide biosensor based on rose-shaped FeMoO4 nanostructures produced by convenient microwave-hydrothermal method

    Liu, Hongying   Gu, Chunchuan   Li, Dujuan   Zhang, Mingzhen  

    In this work, we demonstrated a simple, rapid and reliable microwave-assisted hydrothermal approach to synthesize the uniform rose-shaped FeMoO4 within 10 min. The morphologies of the synthesized materials were characterized by X-ray powder diffraction and scanning electron microscopy. Moreover, a non-enzymatic amperometric sensor for the detection of hydrogen peroxide (H2O2) was fabricated on the basis of the FeMoO4 as electrocatalysis. The resulting FeMoO4 exhibited high sensitivity and good stability for the detection of H2O2, which may be attributed to the rose-shaped structure of the material and the catalytic property of FeMoO4. Amperometric response showed that the modified electrode had a good response for H2O2 with a linear range from 1 mu M to 1.6 mM, a detection limit of 0.5 mu M (S/N =3D 3), high selectivity and short response time. Additionally, good recoveries of analytes in real milk samples confirm the reliability of the prepared sensor in practical applications. (C) 2015 Elsevier Ltd. All rights reserved.
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  • Plasma-assisted synthesis of carbon fibers/ZnO core-shell hybrids on carbon fiber templates for detection of ascorbic acid and uric acid

    Liu, Hongying   Gu, Chunchuan   Hou, Chao   Yin, Zhengzhi   Fan, Kai   Zhang, Mingzhen  

    Carbon fibers/ZnO core-shell hybrids were synthesized in this study by plasma-assisted strategy using carbon fiber templates. The hybrids were characterized by scanning electron microscopy and X-ray diffraction which revealed that the ZnO hybrids were attached on the surface of the carbon nanofibers. The hybrids were used to fabricate microelectrodes, exhibiting a strong electrocatalytic activity toward oxidation of ascorbic acid (AA) and uric acid (UA). Combination of the carbon fibers and ZnO largely increased the surface area of the electrodes, enhanced electron transfer on the electrode surface and widened the distance between oxidation potential of AA and UA. The hybrids therefore endowed the microelectrodes with portability, stability, higher selectivity and sensitivity. A biosensor was thus developed for detection of AA and UA concerning the above properties. The linear range for the AA and UA were 600-2000 mu M and 20-200 p,M, respectively. This work provides a portable and green route for constructing the biomedical sensor with promising prospect for clinical diagnosis. (C) 2015 Elsevier B.V. All rights reserved.
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  • Hollow and porous nickel sulfide nanocubes prepared from a metal-organic framework as an efficient enzyme mimic for colorimetric detection of hydrogen peroxide

    Liu, Hongying   Ma, Huan   Xu, Hanxiao   Wen, Jiajun   Huang, Zhiheng   Qiu, Yubin   Fan, Kai   Li, Dujuan   Gu, Chunchuan  

    Hollow, porous NiS nanocubes were prepared by a hydrothermal method starting from Ni-Co Prussian blue analogue nanocubes as the template. The morphology and structure of the NiS nanocubes were tuned by adjustment of the ion-exchange rate and the degree of chemical etching, and they were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, and nitrogen sorption measurements. The NiS nanocubes are shown to act as a peroxidase mimic that can catalyze the oxidization of 3,3,5,5-tetramethylbenzidine by hydrogen peroxide (H2O2), producing a visible color change, for which the absorbance is best measured at 652 nm. The outstanding activity may result from the unique structure of the NiS nanocubes. The catalytic oxidation follows Michaelis-Menten kinetics and shows a ping-pong mechanism of enzyme action. The findings were used to develop a rapid, sensitive, and selective colorimetric H2O2 assay with a response that is linear in the 4-40 M range with a detection limit of 1.72 M (signal-to-noise ratio of 3).
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  • One-Pot Electrodeposition of NiS Nanoparticles as an Efficient Electrode for Nonenzymatic H 2 O 2 and Glucose Sensors

    Huang, Zhiheng   Gu, Chunchuan   Wen, Jiajun   Zhu, Langlang   Zhang, Mingzhen   liu, Hongying  

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