Bio-sniffer sticks for breath analysis after drinking

Stick-type biochemical gas sensors (bio-sniffer) with alcohol oxidase (AOD) and aldehyde dehydrogenase (ALDH) were developed for convenient analysis of breath ethanol and acetaldehyde, respectively. The sniffer sticks for ethanol and acetaldehyde in the gas phase were constructed by immobilizing enzyme to electrode coated filter paper and hydrophilic PTFE membrane, respectively. The oxidation currents of hydrogen peroxide and NADH, produced by the AOD and ALDH enzymatic reactions, were measured by amperometric analysis. The calibration ranges of the biosensor for ethanol and acetaldehyde in the liquid phase were from 0.05 to 1.41 mmol/l and 1.0 to 250 μmol/l, respectively. And both sniffer sticks were used to measure ethanol and acetaldehyde vapor encountered in breath air after alcohol consumption. Each of the bio-sniffers indicated good gas selectivity based on the substrate specificity of AOD and ALDH as gas recognition material. results of the physiological application, the bio-sniffers were possible to measure the concentration changes in breath ethanol and acetaldehyde after drinking. The concentration values of breath ethanol and acetaldehyde obtained by the sniffers were also consistent with those of commercially available gas detector tubes for ethanol and acetaldehyde.