Simultaneous detection of ethanol, glucose and glycerol in wines using pyrroloquinoline quinone-dependent dehydrogenases based biosensors

Amperometric biosensors based on corresponding dehydrogenases have been developed for the determination of ethanol, glucose and glycerol. The enzymes have been integrated in redox hydrogels using an Os complex-modified non-conducting polymer employed as the electrochemical mediator and poly(ethyleneglycol)-diglycidyl ether (PEGDGE) as the cross-linking agent. The developed biosensors showed a sensitive response to ethanol, glucose and glycerol within the concentration range 2.5–250, 20–800, and 1–200 μM, detection limits of 1.2, 9 and 1 μM, and sensitivities of 220, 87 and 32 mA M−1 cm−2, respectively. The ethanol, glucose and glycerol content of several types of wine was determined with these biosensors, and the results were compared with those obtained by spectrophotometric methods. The developed biosensors have been successfully employed for simultaneous determination of all these substrates at the required sensitivity.