Preparation Of Electrochemical Biosensor Based On Carbon Nanotubes/Polymer Composite Materials

In recent years, the development of multi-walled carbon nanotubes nanocomposites as new chemically modified materials is very rapid because of their unique chemical and electrochemical properties. At present, it have been considered one of the most promising materials, possessing the properties of the individual components with a synergistic effect that would be useful in particular application. In this paper, the incorporation of MWCNTs into conducting polymer has been used to prepare several modified electrode. At the same time, the properties of the modified electrodes were researched by some methods. The main works are summarized as follows:Firstly, electropolymerizing pyrocatechol violet (PCV) on a glassy carbon electrode (GCE) modified with multi-walled carbon nanotubes (MWCNTs), which was characterized by cyclic voltammetry (CV) and scanning electron micrograph (SEM). The result of electrochemical experments showed a favorable catalytic activity toward the reduction of H2O2 with a linear response range from 2.0μM to 2.4 mM and a detection limit of 0.7μM(at a S/N=3).Secondly, prussian blue (PB) nanoparticles modified MWCNTs composites were synthesized using the mixture solution of ferric-(Ⅲ) chloride and potassium ferricyanide at the presence of MWCNTs under ambient conditions by a simple chemical mothod and demonstrated by scanning electronic microscopy (SEM), UV-vis spectroscopy, fourier transform infrared (FTIR) absorption spectrum and cyclic voltammetry (CV). The nanocomposites modified glassy carbon electrode (GCE) showed two well-defined pairs of redox peaks and dramatic catalytic activity toward the electro-oxidation of hydroxylamine with a linear response ranging from 1.5μM to 2.0 mM.Thirdly, a new kind of highly stable prussian blue (PB)/chitosan (CHIT)/multi-walled carbon nanotubes (MWCNTs) as a modified electrode for hydrogen peroxide (H2O2) reduction was proposed. In this work, PB nanoparticles were entrapped within the CHIT film to form a charge transfer complex. The modified electrode showed electrocatalytic activity toward the reduction of H2O2 and was used as an amperometric sensor. The biosensor displayed characteristics of fast response, high sensitivity and good stability for the determination of H2O2.