Preparation of an Electrode That Immobilizes NAD‐Dependent Alcohol Dehydrogenase by Using a Redox Polymer Containing 1,10‐Phenanthroline‐5,6‐dione

A redox polymer (PAHA‐Ru), modified electrode exhibited excellent catalytic activity for the electrochemical oxidation of β‐nicotinamide adenine dinucleotide (NADH). PAHA‐Ru was composed of carboxyl groups and ruthenium complexes containing 1,10‐phenanthroline‐5,6‐dione (phen‐dione). The stability of the PAHA‐Ru film was increased by incorporating poly(diallyldimethylammonium chloride) (PDDA) owing to the formation of a polyelectrolyte complex between the PAHA‐Ru and PDDA. The catalytic efficiency of the oxidation of NADH using the PAHA‐Ru/PDDA‐modified electrode was also greater than that using a PAHA‐Ru‐modified electrode. NAD‐dependent alcohol dehydrogenase (ADH) was entrapped in the PAHA‐Ru/PDDA film on the surface of the glassy carbon electrode. Electrochemical oxidation of ethanol using the ADH‐entrapped electrode was also observed.