AMPEROMETRIC BIOSENSORS BASED ON ELECTROCATALYTIC REGENERATION OF NAD-MODIFIED ELECTRODES( AT REDOX POLYMER)

Amperometric biosensors based on redox polymer-mediated electron trans fer from NADH to carbon paste electrodes, regenerating the NAD+ needed for the dehydrogenase-catalysed reaction, are described. These sensor s, operating around 0 mV vs SCE, can drive an unfavourable equilibrium of a dehydrogenase-catalysed reaction to the product side, and are re agentless in that NAD+ need not be added to the analyte solution. By c overing the sensor with an additional polymer, protection of the elect rode surface, inclusion of water soluble components, exclusion of inte rferents and a diffusion controlled linear response current can be obt ained.