Electroanalytical applications of conductive diamond electrodes

Conductive boron-doped chemical vapor deposited diamond thin film electrode s and microelectrodes were examined for various possible applications in el ectroanalysis in order to exploit their attractive properties, which includ e a wide electrochemical working potential window, low background current a nd high resistance to deactivation. The feasibility of carrying out voltamm etric studies of electrochemical reactions occurring at extreme potentials, either positive or negative, was demonstrated using diamond electrodes, ta king histamine and carbon tetrachloride as examples. High stability and hig h sensitivity of the diamond electrode were demonstrated for the determinat ion of nicotinamide adenine dinucliotide (NADH), which usually fouls glassy carbon and other solid electrodes. A diamond electrode was successfully in corporated into a flow injection system and high sensitivity and excellent reproducibility for the determination of the antibiotic, sulfadiazine, were realized. A detection limit of 100 nM was achieved. Diamond microcrystals grown on tungsten fibers were used for the fabrication of microelectrodes w hich are useful for in vivo analysis and fast reaction kinetic studies.