The Study Of Preparation, Characteristic And Electrochemical Behavior Of Nanogold Modified Carbon Paste Electrode And DNA/Nanogold Double-LayerModified Carbon Fibre Electrode

In this paper, two kinds of chemical modified electrodes were fabricated. One is nanogold modified carbon paste electrode and the other is DNA and nanogold double-layer modified carbon fibre Electrode. The modified electrodes were successfully prepared for the selective detection of neurotransmitters.1, Nanogold Modified Carbon Paste ElectrodeThe wide applications of carbon paste as the matrix of modified electrode are attribute to the simple preparation procedures required, the low residual current, wider potential range, and noise they exhibit, their ability for electrode surface regeneration, and low cost. It is widely used to determine inorganic ions and organic compounds.The nanogold modified carbon paste electrode, which can catalyze oxidation reaction of neurotransmitters, was prepared by absorption of gold nano-particle on the surface of carbon paste. The effect of the concentration of phosphate buffer solution and pH value on the electrochemical behavior of neurotransmitters was studied. This modified electrode can be used to determine the concentration of neurotransmitters in the presence of ascorbic acid.2, DNA and nanogold double-layer modified carbon fibre electrodeDNA and nanogold double-layer modified carbon fibre electrode was effectively prepared. The amount of DNA molecules adsorbed on the surface of gold nano-particle was improved due to the larger surface area and biocompatibility of gold nano-particles. This modified electrode can be used to detect norepinephine in the presence of ascorbic acid due to the negatively-charged acidic end group in DNA which can attract positively-charged norepinephine while repulse negatively-charged ascorbic acid.