Amperometric Biosensor For Ethanol Based On A Phenothiazine Derivative Modified Carbon Paste Electrode

Abstract

A new amperometric biosensor for ethanol, based on carbon paste electrode modified with alcohol dehydrogenase (ADH), polyethylenimine (PEI) and using a phenothiazine derivative (DDDP; 16H,18H-dibenzo[c,1]7,9-dithia-16,18-diazapentacene) as redox mediator for NADH recycling, was developed. The biosensor response is the result of mediated oxidation of NADH, generated in the enzymatic reaction between ADH and ethanol (in the presence of NAD(+)). The biosensor sensitivity (calculated as the ratio I-max/K-M(app)) was 0.035 mA M-1 and the detection limit was 0.26 mM, while the linear response range was from 0.1 to 20 mM ethanol