Nano-engineered flavin-dependent glucose dehydrogenase/gold nanoparticle-modified electrodes for glucose sensing and biofuel cell applications

A three-dimensional composite consisting of the oxygen-insensitive flavin-dependent glucose dehydrogenase, GDH, and Au nanoparticles (NPs) is assembled on a Au surface using an electropolymerization process. The bis-aniline-cross-linked GDH/Au NPs composite reveals effective electrical contact with the electrode (k_et = 1100 s^-1), and the effective bioelectrocatalyzed oxidation is driven by the enzyme/NPs matrix. The GDH/Au NPs-functionalized electrode is implemented as an amperometric glucose sensor, and it reveals superior functions when compared to an analogous glucose oxidase/Au NPs system. The O₂-insensitive GDH/Au NPs composite electrode was further used as an anode in a membraneless glucose/O₂ biofuel cell. The cathode in this system was composed of bilirubin oxidase cross-linked onto a carbon nanotube-modified glassy carbon electrode. The power output of the cell was 32 μW cm^-2.