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Ma M.,Ningbo Entry Exit Inspection and Quarantine Bureau of P.R.C. | Tu X.,South-Central University for Nationalities | Zhan G.,South-Central University for Nationalities | Li C.,South-Central University for Nationalities | Zhang S.,Hubei University for Nationalities
Microchimica Acta

The ionic liquid 1-butyl -3-[3-(N-pyrrole)-propyl]imidazolium tetrafluoroborate was employed to fabricate a glassy carbon electrode (GCE) modified with a porous film of a polymerized ionic liquid. The resulting film electrode was treated with sodium dodecyl sulfonate solution to exchange the terafluoroborate anions by dodecyl sulfonate groups. This was confirmed by X-ray photoelectron spectroscopy. The morphology of the modified GCE was characterized by scanning electron microscopy and revealed a nanoporous surface. The electrochemical properties of this film electrode were studied by electrochemical impedance spectroscopy using the hexacyanoferrate(II/III) system as an electroactive probe. The response to bisphenol A was investigated by voltammetry. Compared to the unmodified GCE, the oxidation potential is positively shifted, and the oxidation peak current is strongly increased. Experimental conditions were optimized and resulted in an oxidation peak current that is linearly related to concentration of bisphenol A in the 10 nM to ~ 10 μM range. The detection limit is 8.0 nM (at S/N = 3). The electrode was successfully applied to the determination of bisphenol A in leachates of plastic drinking bottles, and its accuracy was verified by independent assays via HPLC. [Figure not available: see fulltext.] © 2014 Springer-Verlag Wien. Source

Ma Y.,South-Central University for Nationalities | Zhan G.,South-Central University for Nationalities | Ma M.,Ningbo Entry Exit Inspection and Quarantine Bureau of P.R.C. | Wang X.,South-Central University for Nationalities | Li C.,South-Central University for Nationalities

Highly-ordered zirconium dioxide (ZrO 2) nanotubes were prepared with porous anodic alumina as the template by the liquid phase deposition technique. The obtained ZrO 2 nanotubes were characterized by transmission electron micrograph (TEM) and X-ray diffraction (XRD). A new biocompatible nano-platform for the immobilization of hemoglobin (Hb) was developed by coating a chitosan (CHI) solution, in which the ZrO 2 nanotubes, 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid ([BMIM]BF 4) and Hb were dispersed, onto a glassy carbon electrode surface. Direct electrochemistry of the immobilized Hb on the electrode surface was then investigated. The results indicated that remarkable improvements on the direct electrochemistry of Hb were achieved. In addition, the potential application of the Hb immobilized electrode (Hb/ZrO 2/[BMIM]BF 4/CHI/GCE) in biosensing was demonstrated by the catalytic electrochemical reduction of nitrite ion (NO 2 -) in an aqueous solution. © 2011 Elsevier B.V. Source

Li R.,South-Central University for Nationalities | Liu C.,South-Central University for Nationalities | Ma M.,Ningbo Entry Exit Inspection and Quarantine Bureau of P.R.C. | Wang Z.,Qinzhou University | And 6 more authors.
Electrochimica Acta

1,3-Di(4-amino-1-pyridinium)propane tetrafluoroborate (DAPPT) ionic liquid was successfully synthesized, and was used as a modifier to functionalize graphene nanosheets through covalent binding of amino groups and epoxy groups in an alkaline solution. The as-prepared graphene-DAPPT nanosheets (Gr-DAPPT) were confirmed with transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV/vis and FTIR spectroscopy. A biocompatible platform based on Gr-DAPPT was constructed for the immobilization of hemoglobin (Hb) through a cross-linking step with chitosan and glutaraldehyde. The direct electron transfer and bioelectrocatalytic reaction of Hb immobilized on Gr-DAPPT surface were achieved. A pair of reversible redox peaks of hemoglobin was observed, and bioelectrocatalytic activity toward the reduction of H2O2 was also demonstrated, displaying a potential application for the fabrication of novel biosensors to sense H 2O2. Such results indicated that Gr-DAPPT based interface would be a promising platform for biomacromolecular immobilization and biosensor preparation. © 2013 Elsevier Ltd. All rights reserved. Source

Zhou D.,Zhejiang University of Technology | Zheng X.,Zhejiang University of Technology | Ruan C.,Ningbo Entry Exit Inspection and Quarantine Bureau of P.R.C. | Zhang L.,Zhejiang University of Technology
Key Engineering Materials

CVD diamond is the main trend of future diamond materials. Surface uniformity of CVD diamond film polishing is one of the key technologies to expand the application of CVD diamond. Based on the catalytic polishing method, rotation velocity of the planet wheel is achieved when the lapping plate is in different rotation velocity and different bias distance by mechanics analysis. The lapping surface uniformity is analyzed to find out the best bias distance and velocity ratio by simulating the lapping times of different CVD diamond film with different velocity ratio and bias distance. At last, the lapping planet velocity and bias distance are achieved when polishing is in the best condition. The high uniformity surface can be achieved when polishing is carried out in these parameters. © (2013) Trans Tech Publications. Source

Li C.,South-Central University for Nationalities | Zhan G.,South-Central University for Nationalities | Ma M.,Ningbo Entry Exit Inspection and Quarantine Bureau of P.R.C. | Wang Z.,Qinzhou University
Colloids and Surfaces B: Biointerfaces

Parathion imprinted polymer beads were prepared by free radical polymerization using parathion as template, methacrylic acid as functional monomer, divinyl benzene as cross-linking reagent and 2,2'-azobis(isobutyronitrile) as initiator. The obtained molecularly imprinted beads were characterized with transmission electron micrograph. The rebinding properties of these imprinted beads towards parathion were studied by saturation binding experiments using ultraviolet/visible spectroscopy. Effects of the template, functional monomer, cross-linking reagent and initiator on selective adsorption of parathion were investigated. The high selectivity of the imprinted beads was successfully demonstrated by their selective adsorption of free parathion from an ethanol-water (v/v=1:5) solution. In addition, the parathion imprinted beads were dispersed into dihexadecyl hydrogen phosphate solution at the concentration of 1.0mgmL -1. By coating this solution onto a glassy carbon electrode surface, a molecularly imprinted electrochemical sensor for parathion was obtained. The electrochemical sensor exhibited good selectivity and fast response to parathion. Under optimized experimental conditions, the peak currents were found linearly proportional to the parathion concentration in the range of 1.0×10 -7molL -1 to 1.0×10 -5molL -1 with a detection limit of 5.4×10 -8molL -1 (S/N=3). The developed sensor was successfully employed for the determination of parathion in pear juice samples. © 2011 Elsevier B.V. Source

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