Preparation Of Chemically Modified Electrodes Based On Copper Nanoparticles And Graphene And The Application In Ion Chromatography

The study of chemically modified electrodes is an active field of electroanalytical chemistry presently. Due to their special microstructure, good biocompatibility, accelerating electron transfer rate, nanomaterials have distinguished themselves as widely used materials in the preparation of modified electrodes. Based on detailed reviews on nano-metal particles, polymer film and graphene modified electrode, our research was carried out for preparing two new electrochemical sensors, copper nano-particles/poly-p-aminobenzene sulfonic acid (CuNPs-PABSA) modified glassy carbon electrode (GCE) and copper nano-particles/graphene (CuNPs-Gr) nanocomposite modified glassy carbon electrode. Employing the CuNPs-Gr modified electrode as an amperometric sensor in high performance anion-exchange chromatography (HPAEC), five monosaccharides were analyzed on-line.In chapter one, recent research progress of nanomaterials modified electrodes in the field of electroanalysis is reviewed, with emphasis on the advantagements and preparation of nano-metal particles, polymer film and graphene modified electrodes.In chapter two, a promising CuNPs/PABSA composite was electrochemically synthesized on glassy carbon electrode by electro-polymerization and elecrodeposition. The electrochemical activity and the electrocatalytical behavior of the sensor were characterized by scanning electron microscope (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The modified electrode exhibited good electrocatalytical activity to the reduction of H2O2.In chapter three, a novel CuNPs-Gr/GCE was constructed. The CuNPs-Gr nanocomposite was prepared by simultaneous electrochemical reduction from graphene oxide (GO) and copper ion using cyclic potential scanning on the surface of GCE. The modified electrode showed prominent electrocatalytic oxidation towards monosaccharides. Employing the CuNPs-Gr/GCE as an amperometric sensor in HPAEC, five monosaccharides (fucose, arabinose, galactose, glucose and mannose) were analyzed on-line with high sensitivity, good reproducibility and stablity.