AMPLIFIED BIOSENSING OF ALCOHOL BASED ON BIOCATALYTIC ACCUMULATION OFTHE MEDIATOR

A novel strategy for enhancing the sensitivity of alcohol-dehydrogenas e amperometric biosensors, based on biocatalytic accumulation of the m ediator, is described. By performing the biochemical/chemical step und er open-circuit conditions, it is possible to accumulate the reduced f orm of the Meldola blue mediator, prior to the chronoamperometric quan titation of the enriched layer. Such temporal separation of the recogn ition and transduction events offers a 35-fold sensitivity enhancement (following a 5-min accumulation). Factors influencing the response ar e explored and applicability to various wine samples is illustrated. T he new amplification strategy can be extended to biosensors based on o ther nicotinamide-cofactor dependent dehydrogenases.