LAUSR

Alcohol intoxication leads to road accidents, violence, and the deteriorated health of heavy drinkers. Hence, a convenient means to monitor alcohol consumption with an accuracy and selective manner is a demand by law enforcement personnel, service/hospitality industry, or individual drinkers. We report on a label-free, highly sensitive, and selective alcohol immunosensor based on 2D zinc oxide nanoflakes (ZnO-NFs), which were synthesized on gold-coated flexible polyethylene terephthalate substrates using a single-step sonochemical process. Selective detection of alcohol was achieved via ethyl-glucuronide (EtG) detection by immobilizing EtG antibody (EtG-AB) on the as-synthesized sensing electrodes of ZnO-NFs. The 2D ZnO-NFs provide unique sensing advantages over bulk materials. The cyclic voltammetry and electrochemical impedance spectroscopy measurements demonstrated the sensitivity of 0.032 mA/decade/cm2 in the concentration range of 1 ng/ml to 100 $\mu \text{g}$ /ml which covered the physiological range. The minimum level of detection was determined much lower than 1 ng/ml. Shelf-life studies showed that the presented EtG sensors can be used over two months after the first use without significant performance degradation. Our method and device would help realizing continuous alcohol monitoring in the wearable platform.