Study On Modified Electrode Of Selenium Nanoparticles/Multiwall Carbon Nanotubes

With the widely using of the selenium nanoparticles (NanoSe) and carbon nanotubes(CNTs) in biologic electrocatalysis, new chemical/biosensors have been developed anddesigned, which make high theoretical meanings and application values to exploitapplications of nanomaterials. In this paper, we used modified electrode to research theelectrocatalysis of NanoSe/MWCNTs modified electrode to some amino acids.Preparation of the NanoSe-CTAB/MWCNTs/GC electrode. We used cationic surfactant(CTAB) as dispersant instead of anionic surfactant (SDS), NanoSe-CTAB/MWCNTscomposites were firstly prepared by the chemistry sediment methode and then using thecarbon nanotubes as the carrier. The composite particles obtained were characterized byTransmission electron microscopy (TEM), then as the modified material(NanoSe-CTAB/MWCNTs composites), they were dipped on the glassy carbon(GC)electrode to prepare chemical modified electrode. The electrochemical behaviors ofNanoSe-CTAB/MWCNTs/GC electrode was studied by cyclic voltammetry andelectrochemical impedance spectroscopy. Compared with virginNanoSe-SDS/MWCNTs/GC electrode, the new NanoSe-CTAB/MWCNTs/GC electrodewas smaller capacitance and higher sensibility. The existence of selenium nanoparticlemade the modified electrode more active and catalyzed the electrochemical signals of someamino acids.The electrochemical characteristics of Selenocystine, Cystine, Methionine andTryptophane)on NanoSe-CTAB/MWCNTs/GC electrode are studied with cyclicvoltammetry. As SeCys a example, several parameters of the voltammetric determination,such as the kind of electrolyte, scan rate, pH value, were investigated. It was found that theelectrode process of SeCys on NanoSe-CTAB/MWCNTs/GC electrode was controlled bydiffusion. On NanoSe-CTAB/MWCNTs/GC electrode, the peak current and theconcentration of SeCys, Cys, Met, and Trp had linear relationship, respectively. Accordingto the relationship of the total concentration of four amino acid mixture and their peakcurrent, the total content of SeCys, Cys, Met, and Trp of the selenized samples were 387μg/g, the recovery were 104% and the RSD was 10.8%.