A Sensitive Micro Conductometric Ethanol Sensor Based on an Alcohol Dehydrogenase-Gold Nanoparticle Chitosan Composite

In this paper, a microconductometric sensor has been designed, based on a chitosan composite including alcohol dehydrogenase-and its cofactor-and gold nanoparticles, and was calibrated by differential measurements in the headspace of aqueous solutions of ethanol. The role of gold nanoparticles (GNPs) was crucial in improving the analytical performance of the ethanol sensor in terms of response time, sensitivity, selectivity, and reproducibility. The response time was reduced to 10 s, compared to 21 s without GNPs. The sensitivity was 416 mu S/cm (v/v%) (-1) which is 11.3 times higher than without GNPs. The selectivity factor versus methanol was 8.3, three times higher than without GNPs. The relative standard deviation (RSD) obtained with the same sensor was 2%, whereas it was found to be 12% without GNPs. When the air from the operator ' s mouth was analyzed just after rinsing with an antiseptic mouthwash, the ethanol content was very high (3.5 v/v%). The background level was reached only after rinsing with water.

Automated summary

In this paper, a microconductometric sensor based on a chitosan composite including alcohol dehydrogenase, its cofactor, and gold nanoparticles was designed and calibrated. The presence of gold nanoparticles significantly improved the response time, sensitivity, selectivity, and reproducibility of the ethanol sensor. Compared to without gold nanoparticles, the response time was reduced to 10 s, sensitivity was 11.3 times higher, selectivity factor versus methanol was three times higher, and relative standard deviation was significantly lower.