MICROCHIMICA ACTA
·
2016
·Vol. 183
·期 5
·1651-1657
·
IF 4.831
Rao Hanbing,Ge Hongwei,Lu Zhiwei,Liu Wei,Chen Ziqi,Zhang Zhaoyi,Wang Xianxiang,Zou Ping,Wang Yanying,He Hua,Zeng Xianying
We report that copper nanoclusters (CuNCs) represent a viable fluorescent probe for ascorbic acid. The CuNCs were stabilized by tannic acid and characterized by high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, UV–vis, time-correlated single photon counting and fluorescence spectroscopy. It is found that the fluorescence of CuNCs (at excitation/emission peaks of 355/430 nm) is quenched by ferric ion due to electron-transfer between CuNCs and Fe(III) ions. If ascorbic acid is added, Fe(III) is reduced to Fe(II) and quenching is suppressed. The process is completed within 5 min. Under optimal conditions, a linear relation exists between fluorescence recovery and the concentration of ascorbic acid in the 0.5 μM to 10 μM concentration range. The detection limit is 0.11 μM. The method was applied to the determination of ascorbic acid in (spiked) fruit and vegetables and gave recoveries ranging from 89 to 110 %.
The fluorescence of tannic acid stabilized copper nanoclusters (TA-CuNCs) is quenched by Fe 3+ . Upon addition of ascorbic acid (AA), the redox reaction between Fe 3+ and ascorbic acid converts Fe 3+ to Fe 2+ , and this results in a dramatic fluorescence enhancement of the probe.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2016
·
IF 4.758
Lisi Xie,Abdullah M. Asiri,Xuping Sun
The detection of glucose plays a significant role in diagnostics and management of diabetes and it is thus desired to develop non-noble-metal electrocatalyst for nonenzymatic glucose sensing. This work demonstrates the first use of monolithically integrated copper phosphide nanowire on copper foam (Cu 3 P NW/CF) as an efficient catalyst for electrochemical oxidation of glucose. As a nonenzymatic glucose sensor , this Cu 3 P NW/CF exhibits a low detection limit of 0.32 μM at a signal-to-noise ratio of 3 with a linear range from 0.005 to 1 mM (R 2 = 0.997). It also shows high anti-interference property to other normally co-existing electroactive species including lactose, fructose, ascorbic acid , uric acid , urea, dopiamine, and sucorse as well as excellent resistance to chloride poisoning. Its application for glucose detection in human serum sample is also demonstrated successfully.
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MICROCHIMICA ACTA
·
2016
·Vol. 183
·期 9
·2517-2523
·
IF 4.831
Li Ying,Lin Hechun,Peng Hui,Qi Ruijuan,Luo Chunhua
We describe a chemical exfoliation method for the preparation of MoS 2 nanosheets. The nanosheets were incorporated into poly(3,4-ethylenedioxythiophene) (PEDOT) by electrodeposition on a glassy carbon electrode (GCE) to form a nanocomposite. The modified GCE is shown to enable simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). Due to the synergistic effect of MoS 2 and PEDOT, this electrode displays better properties in terms of electrocatalytic oxidation of AA, DA and UA than pure PEDOT, which is illustrated by cyclic voltammetry and differential pulse voltammetry (DPV). Under optimum conditions and at pH 7.4, the respective sensitivities and best working potentials are as follows: AA: 1.20 A∙mM −1 ∙m −2 , 30 mV; DA: 36.40 A∙mM −1 ∙m −2 , 210 mV; UA: 105.17 A∙mM −1 ∙m −2 , 350 mV. The calculated detection limits for AA, DA and UA are 5.83 μM, 0.52 μM and 0.95 μM, respectively. The modified electrode was applied to the detection of the three species in human urine samples and gave satisfactory results.
MoS 2 nanosheets were prepared by a facile chemical exfoliation method. MoS 2 and poly(3,4-ethylenedioxythiophene) nanocomposite modified glassy carbon electrodes were fabricated, which are shown to enable simultaneous determination of ascorbic acid, dopamine and uric acid with high sensitivity and selectivity.
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Scientific Reports
·
2016
·Vol. 6
·期 1
·1-9
·
IF 5.228
Shen Xiaohui,Wang Qi,Liu Yuhong,Xue Wenxiao,Ma Lie,Feng Shuaihui,Wan Mimi,Wang Fenghe,Mao Chun
Quantitative analysis of superoxide anion (O 2 ·− ) has increasing importance considering its potential damages to organism. Herein, a novel Mn-superoxide dismutase (MnSOD) mimics, silica-manganous phosphate (SiO 2 -Mn 3 (PO 4 ) 2 ) nanoparticles, were designed and synthesized by surface self-assembly processes that occur on the surface of silica-phytic acid (SiO 2 -PA) nanoparticles. The composite nanoparticles were characterized by fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electronic microscopy (SEM), electron diffraction pattern, energy dispersive spectroscopy (EDS) and elemental mapping. Then the electrochemical measurements of O 2 ·− based on the incorporation of SiO 2 -Mn 3 (PO 4 ) 2 onto the surface of electrodes were performed and some satisfactory results were obtained. This is the first report that manganous phosphate (Mn 3 (PO 4 ) 2 ) nanoparticles with shape-controlled, but not multilayer sheets, were utilized for O 2 ·− detection. The surface self-assembly technology we proposed will offer the ideal material to construct more types biosensor and catalytic system for its nanosized effect.
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TALANTA
·
2016
·
IF 4.035
Jian Li,Ning Zhang,Qingqing Sun,Zhanming Bai,Jianbin Zheng
A novel imprinted silica matrix-poly(aniline boronic acid) hybrid for electrochemical detection of dopamine (DA) was developed. Boronic acid functionalized conducting polymer was electrochemically prepared on Au electrode. The number of covalent binding sites toward DA templates was controlled by potential cycles. A precursory sol solution of ammonium fluorosilicate (as cross-linking monomer) containing DA was spin-coated on the polymer modified electrode . Under NH 3 atmosphere, the hydroxyl ions were generated in the solution and catalyzed the hydrolysis of fluorosilicate to form silica matrix. After this aqueous sol-gel process, an inorganic framework around the DA template was formed and the imprinted hybrid for DA was also produced. As revealed by scanning electron microscopy, UV-vis spectroscopy and cyclic voltammetry characterization, DA was embedded in the imprinted hybrid successfully. The affinity and selectivity of the imprinted hybrid were also characterized by cyclic voltammetry . The imprinted hybrid showed higher affinity for DA than that for epinephrine, and little or no affinity for ascorbic acid and uric acid due to the combined effects of covalent interaction, cavities matching and electrostatic repulsion. The imprinted hybrid sensor exhibited a quick response (within 5 min) to DA in the concentration range from 0.05 to 500 μmol L −1 with a detection limit of 0.018 μmol L −1 . The prepared sensor was also applied to detect DA in real samples with a satisfactory result.
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ANALYTICAL CHEMISTRY
·
2017
·
IF 6.32
Zhijiao Tang,Zhenhua Lin,Gongke Li,Yuling Hu
Fluorescent amino nitrogen quantum dots (aN-dots) were synthesized by microwave-assisted method using 2-azidoimidazole and aqueous ammonia. The aN-dots have a nitrogen component up to 40%, which exhibit high fluorescence quantum yield, good photostability, and excellent biocompatibility. We further explored the use of the aN-dots combined with AuNPs as a nanoprobe for detecting fluorescently and imaging of cysteine (Cys) in complex biological samples. In this sensing system, the fluorescence of aN-dots was quenched significantly by gold nanoparticles (AuNPs), while the addition of Cys can lead to the fluorescence signal recovery. Furthermore, we have demonstrated that this strategy can offer a rapid and selective detection of Cys with a good linear relationship in the range of 0.3–3.0 μmol/L. As expected, this assay was successfully applied to the detection of Cys in human serum and plasma samples with recoveries ranging from 90.0% to 106.7%. Especially, the nanoprobe exhibits good cell membrane permeability and excellent biocompatibility by CCK-8 assay, which is favorable for bioimaging applications. Therefore, this fluorescent probe ensemble was further used for imaging of Cys in living cells, which suggests our proposed method has strong potential for clinical diagnosis. As a novel member of the quantum-dot family, the aN-dots hold great promise to broaden applications in biological systems.
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CHINESE CHEMICAL LETTERS
·
2016
·
IF 1.947
Li-Qing Xie,Yan-Hui Zhang,Fei Gao,Quan-An Wu,Piao-Yang Xu,Shan-Shan Wang,Ning-Ning Gao,Qing-Xiang Wang
A nanocomposite of polyaniline/reduced graphene oxide (PANI-rGO) was synthesized using a hydrothermal method. The product was characterized by FT-IR, Raman spectra, XRD, SEM and TEM. Then the hybrid material of PANI-rGO and Nafion (PANI-rGO-NF) was prepared and used to modify glassy carbon electrode for the trace determination of dopamine (DA) employing differential pulse voltammetry (DPV). It was found that the hybrid material showed good catalytic activity toward the oxidation of DA, and no response to ascorbic acid (AA) and uric acid (UA) was observed, suggesting a high selectivity of the sensor toward DA. The peak currents were linearly correlated with the concentration of DA in the range from 0.05 μmol/L to 60.0 μmol/L (R = 0.996) and 60.0 μmol/L to 180.0 μmol/L (R = 0.996) with a detection limit of 0.024 μmol/L (S/N = 3). The modified electrode also exhibited excellent repeatability and stability.
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Journal of Physical Chemistry C
·
2016
·
IF 4.509
Yinghan Yan,Cuiling Zhang,Wei Gu,Caiping Ding,Xinchang Li,Yuezhong Xian
A facile and eco-friendly approach for the synthesis of water-soluble WS2 quantum dots (QDs) was developed via ultrasonication and a hydrothermal process from bulk WS2. In this strategy, the dispersity of bulk WS2 in aqueous phase was improved with the aid of a surfactant (hexadecyltrimethylammonium bromide, CTAB), which could shorten the exfoliation time and improve the exfoliation efficiency to form layered WS2 nanosheets. Through hydrothermal treatment, the nanosheets were further scissored into QDs with high quality. The QDs show excellent features with narrow size distribution, good water solubility, and stable fluorescence. We find that the fluorescence of WS2 QDs can be quenched by Fe3+ through photoinduced electron transfer, and a wide detection linear range for Fe3+ is acquired. It indicates that WS2 QD can be used as a “turn-off” probe for Fe3+. In the presence of lipoic acid (LA), the fluorescence was recovered due to the stronger interaction between LA and Fe3+ than WS2 QDs. A “turn-on” sensor for LA was developed with a linear range from 1 to 10 μM and a detection limit of 0.59 μM. The strategy might be suitable for the facile synthesis of other water-soluble transition metal dichalcogenide QDs. It is expected that the water-soluble QDs have great potential applications in biological system.
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JOURNAL OF SEPARATION SCIENCE
·
2017
·Vol. 40
·期 21
·4160-4167
·
IF 2.557
Jing Wang,Dongfang Shi,Meizhu Zheng,Bing Ma,Jing Cui,Chunming Liu,Chengyu Liu
Natural products have become one of the most important resources for discovering novel xanthine oxidase inhibitors, which are commonly employed in the treatment of hyperuricemia and gout. However, to date, few reports exist regarding the use of monoterpene glycosides as xanthine oxidase inhibitors. Thus, we herein report the use of ultrafiltration coupled with liquid chromatography in the screening of monoterpene glycoside xanthine oxidase inhibitors from the extract of Paeonia lactiflora ( P. lactiflora ), and both high-performance counter-current chromatography and medium-pressure liquid chromatography were employed to separate the main constituents. Furthermore, the xanthine oxidase inhibitory activities and the mechanisms of inhibition of the isolated compounds were evaluated using a multi-mode microplate reader by Molecular Devices. As a result, three monoterpene glycosides were separated by combined high-performance counter-current chromatography and medium-pressure liquid chromatography in purities of 90.4, 98.0, and 86.3%, as determined by liquid chromatography. These three compounds were identified as albiflorin, paeoniflorin, and 1- O -β-ᴅ-glucopyranosyl-8- O -benzoylpaeonisuffrone by electrospray ionization tandem mass spectrometry, and albiflorin and paeoniflorin were screened as potential xanthine oxidase inhibitors by ultrafiltration with liquid chromatography. The evaluation results of xanthine oxidase inhibitory activity corresponded with the screening results, as only albiflorin and paeoniflorin exhibited xanthine oxidase inhibitory activity.
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TALANTA
·
2016
·
IF 4.035
Yan Zhang,Jingjing Jiang,Min Li,Pengfei Gao,Ying Zhou,Guomei Zhang,Shaomin Shuang,Chuan Dong
Herein, a novel, high sensitive, and specific colorimetric sensor for cysteine (Cys) based on pectinase protected gold nanoparticles (P@AuNPs) has been demonstrated for the first time. The P@AuNPs were synthesized by “MW-assisted heat method” and were characterized by UV–vis, TEM , FT-IR and zeta potential techniques. Cys could cause the aggregation of P@AuNPs due to formation of the strong covalent Au-S bond and electrostatic binding. As the Cys concentration increased, the color of the solutions gradually changed from wine-red to blue as well as the large absorption band shifted from 523 to 650 nm upon P@AuNPs aggregation. In addition, various experimental parameters such as pH, the amount of P@AuNPs and incubation time were investigated for the optimum sensing conditions. The concentration of Cys could be determined by monitoring with the naked eye or a UV–vis spectrometer. The proposed colorimetric sensor showed an extreme selectivity toward the determination of Cys in the presence of 20-fold all other different interferents. Under optimum conditions, this method exhibited two good linear ranges from 4.85×10 −9 to 3.02×10 −4 M (R 2 =0.996) and 3.25×10 −3 to 1.03 × 10 −2 M (R 2 =0.999), with a low detection limit of 4.6×10 −9 M. Moreover, this colorimetric sensor was successfully applied to the detection of Cys in human urine samples, demonstrating its great value for practical application in biological systems.
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JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2016
·
IF 2.822
Juan Chang,Wei Xiao,Ping Liu,Xiaoning Liao,Yangping Wen,Ling Bai,Linjian Li,Mingfang Li
Uric acid (UA), a waste product of purine derivatives catabolism, is one of the main culprits of gout. In this paper, a simple and sensitive method for the simultaneous voltammetric detection of UA and the most common purine derivatives like guanine (G) and adenine (A) in human serum and lettuce samples was successfully realized using glassy carbon electrode (GCE) modified with the water-processable nanotubular composites consisting of both halloysite nanotubes (HNTs) and carboxyl-functionalized multi-walled carbon nanotubes ( f MWCNTs) that were well dispersed by carboxymethyl cellulose (CMC). A water-processable HNTs hybrid nanotubes with f MWCNTs were successfully prepared using CMC assist, and the CMC-HNTs- f MWCNTs composites were characterized by scanning electron microscopy, fourier-transform infrared spectroscopy, transmission electron microscope, electrochemical impedance spectroscopy , cyclic voltammetry and chronocoulometry . CMC-HNTs- f MWCNTs/GCE displayed enhanced electrode stability in water, effective surface area, adhesive property and adsorption capacity, and electrocatalytic activity for the oxidation of UA, G and A, which could simultaneously detected three purine derivatives in linear ranges from 1 to 130 μM with a limit of detection (LOD) of 0.5 μM for UA, 0.05 to 9 μM with LOD of 0.018 μM for G, and 0.3 to 25 μM with LOD of 0.19 μM for A, respectively. The as-fabricated sensor displayed high sensitivity, low detection limit, good sensing stability, remarkable feasibility, and satisfactory practicality.
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Materials Science & Engineering C-Materials for Biological Applications
·
2016
·
IF 3.42
Wenqin Wu,Beibei Yu,Huimin Wu,Shengfu Wang,Qinghua Xia,Yu Ding
Different phases of cobalt sulfides have been fabricated by one-pot hydrothermal method. Comparing all of the prepared materials, and the results revealed that CoS was the most conductive and could accelerate electron transfer. The CoS presented tremella-like and excellent catalytic activities towards hydrogen peroxide and glucose. The sensor based on CoS performed amperometric sensing of hydrogen peroxide in a linear range between 5.00 μM and 14.82 mM. Meanwhile, sensing of glucose with double-linear range, one is between 5.00 μM and 1.10 mM, the other is between 1.20 mM and 10.20 mM. These due to the fact that more and more intermediate species absorb onto electrode surface with increasing the concentration of glucose, which limit the following glucose oxidation. Furthermore, the hydrogen peroxide and glucose sensors based on tremella-like CoS also exhibited excellent selectivity, stability, and reproducibility. Thus, the sensor showed potential utilities in hydrogen peroxide and glucose detection.
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高影响因子
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