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Baoshan, China

Yang G.,Wuhan University | Yang G.,Baoshan University | Zhao F.,Wuhan University | Zeng B.,Wuhan University
Electrochimica Acta | Year: 2014

A novel electrochemical sensor was presented for the determination of metronidazole (MDZ), which was based on a graphene (r-GO) modified magnetic-controlled glassy carbon electrode (MCGCE) and magnetic molecularly imprinted polymer (mag-MIP). The mag-MIP was immobilized on the r-GO modified MCGCE (r-GO/MCGCE) or removed from it by freely installing a magnet into MCGCE or not. The as-prepared mag-MIP was used to recognize MDZ from sample solutions to obtain mag-MIP-MDZ. Then, the mag-MIP-MDZ was separated from the solution using an external magnet, rinsed and dispersed in little buffer solution by ultrasound, and part of the suspension was immediately dropped on the r-GO/MCGCE for electrochemical detection. After detection, the magnet was removed from the MCGCE, and the mag-MIP was collected using an external magnet. Afterwards, the magnet was installed into the MCGCE again for the next detection. The used mag-MIP was collected and totally eluted for reuse. The factors concerning the assay strategy were carefully investigated, including preparation conditions of mag-MIP, modified electrode and determination variables. Under the optimal conditions, the electrochemical sensor offered an excellent response to MDZ, the linear detection range was 3.2 × 10-8 ∼ 3.4 × 10-6 mol L-1 and the detection limit was 1.2 × 10-9 mol L-1. The method was applied to the determination of MDZ in real samples with satisfactory results. © 2014 Elsevier Ltd. Source


Yang G.,Wuhan University | Yang G.,Baoshan University | Zhao F.,Wuhan University | Zeng B.,Wuhan University
Biosensors and Bioelectronics | Year: 2014

A novel electrochemical sensor is presented for the determination of cefotaxime (CEF), which is constructed by molecularly imprinted polymer (MIP), gold networks@IL (IL, 1-butyl-3-methylimidazolium tetrafluoroborate, [BMIM][BF4]) (GNWs@IL), porous platinum nanoparticles (PPNPs) and carboxyl graphene (COOH-r-GO). The GNWs@IL is prepared by directly reducing HAuCl4 with sodium citrate in [BMIM][BF4] aqueous solution. The PPNPs are well embedded in GNWs@IL due to the adhesion of IL to form GNWs@IL-PPNPs suspension, which is coated on a COOH-r-GO modified glassy carbon electrode to construct a porous three-dimensional networks modified electrode. Then, MIP is prepared by cyclic voltammetry at the modified electrode, using CEF as template and o-phenylenediamine as monomer. The factors concerning this assay strategy are carefully investigated. Under the optimal conditions, the electrochemical sensor offers an excellent response for CEF, the linear response range is 3.9×10-9~8.9×10-6molL-1 and the detection limit is 1.0×10-10molL-1. The electrochemical sensor has been applied to the determination of CEF in real samples with satisfactory results. © 2013 Elsevier B.V. Source


Yang G.,Wuhan University | Yang G.,Baoshan University | Zhao F.,Wuhan University
Biosensors and Bioelectronics | Year: 2014

Herein, we present a novel electrochemical sensor for the determination of chloramphenicol (CAP), which is based on multiwalled carbon nanotubes@molecularly imprinted polymer (MWCNTs@MIP), mesoporous carbon (CKM-3) and three-dimensional porous graphene (P-r-GO). Firstly, 3-hexadecyl-1-vinylimidazolium chloride (C16VimCl) was synthetized by using 1-vinylimidazole and 1-chlorohexadecane as precursors. Then, C16VImCl was used to improve the dispersion of MWCNT and as monomer to prepare MIP on MWCNT surface to obtain MWCNTs@MIP. After that, the obtained MWCNTs@MIP was coated on the CKM-3 and P-r-GO modified glassy carbon electrode to construct an electrochemical sensor for the determination of CAP. The parameters concerning this assay strategy were carefully considered. Under the optimal conditions, the electrochemical sensor offered an excellent response for CAP. The linear response ranges were 5.0×10-9-5×10-7molL-1 and 5.0×10-7-4.0×10-6, respectively, and the detection limit was 1.0×10-10molL-1. The electrochemical sensor was applied to determine CAP in real samples with satisfactory results. © 2014 Elsevier B.V. Source


Yang G.,Wuhan University | Yang G.,Baoshan University | Zhao F.,Wuhan University | Zeng B.,Wuhan University
Talanta | Year: 2014

In the present study, a suspension solution containing anisotropic gold nanoparticle (GNP), chitosan (CHIT) and ionic liquid (IL, i.e. 1-butyl-3-methylimidazolium tetrafluoroborate, [BMIM][BF4]), is prepared by reducing HAuCl4 with sodium citrate in CHIT-IL aqueous solution. The hybrid solution is coated on a graphene (r-GO) modified glassy carbon electrode to construct an electrochemical sensor for the determination of theophylline (TP) and caffeine (CAF). The obtained hybrid film shows rough surface, and anisotropic GNPs are well dispersed on it. The factors concerning this assay strategy are carefully investigated, including the components of the hybrid film, the concentrations of r-GO, HAuCl4 and IL, and the pH of buffer solution. Under the optimized conditions, the linear response ranges are 2.50×10-8-2.10×10-6 mol L-1 and 2.50×10-8-2.49×10-6 mol L-1 for TP and CAF, respectively; the detection limits are 1.32×10-9 mol L-1 and 4.42×10-9 mol L-1, respectively. The electrochemical sensor shows good reproducibility, stability and selectivity, and it has been successfully applied to the determination of TP and CAF in real samples. © 2014 Elsevier B.V. Source


Yang G.,Wuhan University | Yang G.,Baoshan University | Zhao F.,Wuhan University
Electrochimica Acta | Year: 2015

We described a novel electrochemical sensor for amoxicillin (AMOX), which was constructed by multiwalled carbon nanotubes@molecularly imprinted polymer (MWCNTs@MIP), single walled carbon nanotube (SWCNT) and dendritic Pt-Pd nanoparticle (NP). Firstly, ionic liquid (IL, i.e. 3-propyl-1-vinylimidazolium bromide) was grafted onto MWCNTs surface to form MWCNTs@IL by using an ionic exchange strategy. Then, the resulting MWCNTs@IL was used as monomer to synthesize MWCNTs@MIP. Meanwhile, dendritic Pt-Pd bimetallic NP was prepared by using hexadecylpyridinium chloride and hexamethylenetriamine as synergetic structure-directing agents, and then it was dispersed into SWCNT suspension. After that, the hybrid suspension was dropped on a glassy carbon electrode, followed by coating with MWCNTs@MIP. Under the optimal conditions, the obtained sensor presented linear response to AMOX in the ranges of 1.0×109 ∼ 1.0×106molL1 and 1.0×106 ∼ 6.0×106, respectively, and its detection limit was 8.9 × 1010 mol L1. This sensor was used to detect AMOX in real samples with satisfactory results. © 2015 Elsevier Ltd. All rights reserved. Source

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