– Glucose dehydrogenase (GDH) is an oxidoreductase enzyme that facilitates the oxidation of β-D-glucose into β-D-glucono-1,5-lactone, while concurrently reducing cofactor NADP+ to NADPH, and to a lesser degree, NAD+ to NADH. It can utilize both NAD+ and NADP+ as cofactors and serves in the regeneration of NADH and NADPH [1] [2].