Electrochemical Determination of Biomokcules with ECR Sputter Deposited Carbon Film Electrodes

摘要

The carbon thin film deposited by electron cyclotron (ECR) sputtering method shows wide potential window and low capacitive current and therefore applied for measuring various biomolecules with high oxidation potentials including histamine and NADH and nucleotides. The film consists of sp3 and sp2 mixed bonds and has equivalent mean scratch hardness to the diamond. The structure of the film from TEM image is different from usual graphite carbon. In 0.05 M H2SO4 solution, the potential window (±500 uA/cm2) of the film (deposited with acceleration to the positive direction is about 2.0 V which is much higher than that of glassy carbon and about 0.1 V lower than that of boron doped diamond. As a result, we can measure oxidation potentials of 4 nucleic acid and oligonucleotides. The fouling of the ECR carbon films with irreversible electroacive species such as bisphenol A were greatly suppressed since the film has very flat surface and low surface oxygen concentration.