Wearable glucose/oxygen biofuel cell fabricated using modified aminoferrocene and flavin adenine dinucleotide-dependent glucose dehydrogenase on poly(glycidyl methacrylate)-grafted MgO-templated carbon

We have developed a new electrode material for biofuel cells (BFCs) in which a mediator was covalently immobilized on MgO-templated porous carbon (MgOC). Grafted MgOC (GMgOC) was prepared by modifying poly (glycidyl methacrylate) on the MgOC surface by electron beam graft polymerization. Furthermore, aminoferrocene (AmFc) and flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH) were immobilized by covalent bonding between the amino group and pendant glycidyl group. The current density estimated by cyclic voltammetry was approximately 21.2 mA cm(-2) at 0.49 V in a 1 mol L-1 phosphate buffer containing 100 mmol L-1 glucose. The current value was stable because of the suppression of AmFc elution after 10 h of continuous measurement. A glucose/O-2 BFC was fabricated by combining an anode modified with FADGDH/poly(GMA)-modified AmFc and a BOD/2,2 '-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)-modified water-repellent cathode and applying 1 mol L-1 PBS containing 300 mmol L-1 glucose (pH 7.0). The BFC showed a high power density of 3.6 mW cm(-2). We fabricated a wearable BFC based on hydrogels with ortho hydroquinone groups that can maintain adhesiveness on human skin. The power density of the wearable cell was 0.42 mW cm(-2) at 0.38 V in the air, which is sufficient output to power a small electronic device.