The Study On Fabrication Of Functionalized Nano-Materials And Electrochemical Sensing

In this study, electrical analysis technology have been mainly used to the determination of the target so as to realize the experimental goal of determination of the harmful subjects or biomacromolecules in the environment. Three-electrode system has been utilized, and the glassy carbon electrode used as the working electrode, the surface of which has been modified with the novel nanomaterial by dispensing method or electrochemical deposition method. Then, the detection analysis of environmental hormone phenol and xanthine have been studied using the modified electrode. The main studies are as follows:(1)β-cyclodextrin functionalized graphene nano platelets for electrochemical determination of triclosan: graphene nanoplatelets(GNP) was chosen as the carbon substrate, then the β-Cyclodextrin was added to the carbon substrate to form a macromolecular layer. The modified electrode β-CD/GNP/GCE has combined the ability of super electron transport rate and adsorption property attributed to the grapheme and the ability of specific molecular selection ability attributed to the β-CD. Finally, the modified electrode has been successfully used to determine the environmental hormone —triclosan. By applying differential pulse voltammetry, the monitoring of tricosan in the range of 2.0 μM to 100 μM was realized, and the limit of detection is 6.0×10-7 mol /L.(2) Electrochemical behavior research of octyl phenol on the β-CD loaded reduced graphene oxide modified electrode(RGO-β-CD/GCE): In this work, the main idea is still to combine the grapheme and β-CD, the most point is that chemical reduction method has been introduced to produce grapheme from grapheme oxide, which have been mixed with someβ-CD before, then the composite nanomaterial RGO-β-CD has been successfully fabricated. Compared to the grapheme, the hydrophily of this nanomaterial has been improved due to the number of hydroxyl groups of β-CD loaded on the surface of Grapheme layers. Actually, the RGO-β-CD/GCE modified electrode has been applied to the determination of the octyl phenol. Under the optimum conditions, the oxidation peak current was found to be linearly dependent on the concentration of xanthine in the range from 8.0×10-7~1.0×10-5 mol /L, with a detection limit of 2.4×10-7 mol /L.(3) Electrochemical deposition of sol-gel/gold nanoparticles composite film and its application in the determination of xanthine: In this research,use tetraethylort--hosilicate as silicon source, and hydrolysis of silica precursora. Then sol-gel/gold nanoparticles modified electrode was prepared by electrodeposition under constant potential conditions. The nano-interface of the modified eclectrode has been characterized with cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy method. Electrochemical behavior of xanthine on the modified electrode was investigated. Experimental conditions such as sol-gel/gold nanoparticles deposition time, p H value were studied.Under the optimum conditions, the oxidation peak current was found to be linearly dependent on the concentration of xanthine in the range from 2.5×10-7-1.5×10-3 mol /L. The linear relationship is expressed as Ιp(A) = 5.714×10-7+ 0.0644c(mol/L), with a detection limit of 8.3×10-8 mol /L.