A Low-cost Electrochemical Biosensor With Copper and Aluminum Electrodes for Alcohol Detection

Abstract

Drunk driving is one of the leading causes of traffic accidents worldwide. This research aimed to develop a low-cost paper-based electrochemical biosensor for alcohol concentration measurement utilizing an alcohol oxidation reaction catalyzed by the alcohol oxidase enzyme. The anode and cathode electrodes of the paper-based biosensor were made of copper and aluminum tapes, respectively, and were coupled to electronic sensor modules for signal reading and processing. The results demonstrated that the oxidase enzyme was necessary for the biosensor to function, resulting in a linear signal response with alcohol concentrations ranging from 9 to 36 mM. The sensitivity of the enzyme-coated biosensor was significantly higher than that of the enzyme-free biosensor. Moreover, measuring the biosensor’s electrochemical signal by current was found to yield a higher sensitivity (0.5499 – 1.0915 μA/mM) than voltage measurements (0.0010 – 0.0022 V/mM). The maximum sensitivity of 1.0915 μA/mM (R² = 0.8410) was obtained by measuring the current near the reaction zone at the center of the biosensor sheet. The optimum enzyme concentration that gave rise to the maximum sensitivity was found to be 20% v/v with a detection limit of 1.9478 mM. The biosensor was estimated to cost approximately 12 baht, considerably cheaper than the current breathalyzer-based method, and could therefore be further developed as a portable, disposable alcohol test pad to prevent drunk driving accidents.