Development of a novel enzyme/semiconductor nanoparticles system for biosensor application

Nanosized semiconductor crystals can increase efficiency of photochemical reactions and can be effectively coupled to biomolecular units, such as enzyme, to generate novel photoelectrochemical systems. In this work, nanocrystalline CdS has been synthesized by using a microemulsive system and immobilised by self-assembling on a gold electrode in order to prepare, combined with formaldehyde dehydrogenase (FDH) enzyme, a biological-inorganic hybrid able to perform catalytic oxidation of formaldehyde. The preliminary results indicate that quantum-sized CdS layer on gold, in close contact with the enzyme, is an effective photoactive material to replace the NAD+/NADH role as charge transfer in the enzymatic reaction.