Nicotinamide adenine dinucleotide-dependent (NAD) enzymes are used by a wide-spread of dehydrogenases which have been used in a large portion of enzymatic fuel cells (EFCs) to date. The oxidation of an EFC’s fuel (such as glucose) results in the generation of enzymatically-generated diffusive reduced cofactor (NADH). Various electrocatalysts and mediators have been employed to electro-oxidize NADH at low potential, such as phenothiazines and rhodium catalysts.^{1, 2} Naphthoquinones and anthraquinones have also been employed for NADH oxidation in high power EFCs, however their use typically requires an additional enzyme to mediate electron transfer between the quinone and NADH (diaphorase).³

            We report the use of a naphthoquinone redox polymer to oxidize NADH, enzymatically generated from glucose oxidation by NAD-dependent glucose dehydrogenase. The naphthoquinone redox polymer serves as a support for enzyme immobilization. Additionally, NADH is oxidized without the requirement of diaphorase.⁴

References

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2.         B. Reuillard, A. Le Goff and S. Cosnier, Anal. Chem., 2014, 86, 4409-4415.

3.         H. Sakai, T. Nakagawa, Y. Tokita, T. Hatazawa, T. Ikeda, S. Tsujimura and K. Kano, Energy & Environmental Science, 2009, 2, 133-138.

4.         S. Abdellaoui, R. D. Milton, T. Quah and S. D. Minteer, Chem. Commun., 2016, DOI: 10.1039/C5CC09161F.