Caw Modified Electrode Catalysis Of Small Molecules Of Biological Electricity

The paper reports the research results of the spectra of carbon atom wires (CAW), and, of the electrocatalysis of CAW modified electrodes for the electrochemical processes of ascorbic acid, dopamine and dihydronicotinamide adenine dinucleotide (NADH). Various measurements including HRTEM, IR, UV, Raman, ICP, XPS, Elemental Analysis and Chemical Analysis were performed to characterize the morphology, structure and compositions of CAW respectively. The electrocatalysis and stability of CAW modified electrode were studied by cyclic voltammetry, compared with the related reports made by other authors.CAW, similar to carbyne in structure in a sense, were fabricated at high temperature by a pyrolytic process from potato starch as a carbonaceous source in the presence of a catalyst of ferric metals under the stream of Ar/H2 mixture. The diameter of CAW, around 0.2nm, is compared to the diameter of a carbon atom (0.154nm) in HRTEM images. XPS and Elemental Analysis revealed the material consisted of carbon (92.4wt%), hydrogen (2.0wt%) and oxygen (5.6wt%). IR and Chemical Analysis identified the alcoholic hydroxyl groups and carboxylic acid groups presented on CAW, and even more amounts of such groups produced in the process treated by concentrated nitric acid. UV and Raman spectra indicated that the portion of CAW dissolved in hexane were structured by the cumulated double bonds ( = C=C =)n with the short chain consisted of less than 10 carbon atoms.The CAW modified electrode was prepared by a physical absorption method on the substrate of glassy carbon. The phosphate buffer solution (PBS) of pH 6.80 was chosen as the supporting electrolyte in the electrochemical measurements. The anodic and cathodic peaks on CVs of the CAW modified electrode in the PBS solution were attributed to the oxidation of alcoholic hydroxyl groups and the reduction of carboxylic acid groups respectively. The slope in the linear relationship of redox peak potentials and pH values suggested the involvement of H+ in the electrode reactions, with one H+ transferred, meanwhile accompanied by one electron transferred as well. The linear dependence of redox peak currents on ccan rates showed the redox peaks on the CVs arising from the redox of a couple on the electrodesurface, not in the solution.Cyclic voltammetry was used to investigate the electrocatalysis of the CAW modified electrode on ascorbic acid, dopamine and dihydronicotinamide adenine dinucleotide (NADH) respectively. The experimental results showed: (1) the anodic peak potential shifted negatively by 0.379V, the anodic peak current increased by 73% for ascorbic acid; (2) the anodic peak potential shifted negatively by 0.198V, the cathodic peak potential shifted positively by 0.108V, the anodic peak current increased by about 9 times for dopamine; and (3) the anodic peak potential shifted negatively by 0.390V, the anodic peak current increased by 4.48 times for NADH on the CAW modified electrode, compared with a glassy carbon electrode. An additional cathodic peak on 0.163V was detected on the CAW modified electrode treated by nitric acid, compared with other electrodes. In addition, the CAW modified electrode treated by nitric acid could determine the concentration of dopamine in the presence of highly concentrated ascorbic acid and had a separation between the anodic peaks of ascorbic acid and dopamine as great as 0.298V, a so great separation never reported by other authors so far as we know. The CAW modified electrode is stable and can be used for many times in its application.As the experimental results shown, the CAW modified electrode, especially the nitric acid treated one, possesses an excellent activity of electrocatalysis in the electrochemical reactions of ascorbic acid, dopamine and dihydronicotinamide adenine dinucleotide (NADH) respectively.