An all-solid-state amperometric ethanol sensor

An all-solid-state pellet electrode for ethanol determination has been developed and compared with the membrane-layered sensor. It is found that the new pellet electrodes have reliable responses (current vs. concentration) to ethanol from 0.1 to 10 m with response times of about 2 min. The current response decreases about 10% h⁻¹ during continuous operation, compared with a drop of 50% h⁻¹ with normal membrane electrodes. Fresh electrodes can be stored in a freezer for 2 weeks without apparent activity loss. The measurement procedure is convenient and it is probable that reproducible, disposable electrodes can be made at low cost. This format is general and can easily be extended to many other systems with β-NAD⁺/NADH as coenzyme.