The basis of this alcohol sensor is the oxidation of ethanol by NAD* with alcohol dehydrogenase as the catalyzing enzyme. The NADH formed is detected electrochemically at 700 mV versus a Ag/AgCl-electrode. The electrode used is a carbon paste electrode with the enzyme and the cofactor mixed into the paste. The sensor can be used up to concentrations of approximately 0.15 Mol/1 (i. e. 1 Vol%), with a response time of 15 s and a stability of at least 7 days.