High Sensitive Amperometric Detection of Glucose using Conductive DLC Electrode in Higher Potential Region

摘要

The possibility of a high sensitive amperometric detection of glucose using electrochemically-generated hydroxyl radicals at N-doped DLC was examined. Flow injection analytical system using N-doped DLC as an electrode of electrochemical detector showed higher performance of glucose detection in a potential region of oxygen evolution (＞3.6 V vs. Ag|AgCl). Linear dynamic range was 5 orders of magnitude (1 μM to 10 mM) and theoretical detection limit (S/N = 3) was 1.37 mM at 3.6 V vs. Ag|AgCl. In addition to glucose, linear relations between values of response current and of sample concentration were observed in molecules easily oxidized by OH radicals (ascorbic acid, 2-propanol, ethyl acetate and ethyl acetoacetate). The oxidation of glucose mediated by OH radicals generated at N-doped DLC in higher potential region is included in the mechanism of amperometric glucose detection at N-doped DLC.