Scaffold electrodes based on thioctic acid-capped gold nanoparticles coordinated Alcohol Dehydrogenase and Azure A films for high performance biosensor

• Thiotic acid capped gold nanoparticles coordinated to Alcohol Dehydrogenase.
• Azure A electrografted films as NADH sensing platforms
• Alcohol Dehydrogenase-AuNPs bioconjugates onto Azure A films for ethanol biosensing.
• Rapid determination of ethanol in wine

Nanometric size gold nanoparticles capped with thiotic acid are used to coordinate with the Zn (II) present in the catalytic center of Alcohol Dehydrogenase (ADH). In combination with the NADH oxidation molecular catalyst Azure A, electrografted onto carbon screen-printed electrodes, they are used as scaffold electrodes for the construction of a very efficient ethanol biosensor. The final biosensing device exhibits a highly efficient ethanol oxidation with low overpotential of − 0.25 V besides a very good analytical performance with a detection limit of 0.14 ± 0.01 μM and a stable response for more than one month.