Enhanced Charge Transport in Enzyme-Wired Organometallic Block Copolymers for Bioenergy and Biosensors

Wiring of glucose oxidase (GOx) onto electrode surface was successfully achieved by cross-linked networks of organometallic block copolymers comprising electroactive ferrocene moieties and chemically cross-linkable diene groups, poly(ferrocenyldimethylsilane-b-isoprene)s (PFS-PIs). Different nanoscale morphologies of PFS-PIs, i.e., bicontinuous structure, nanowires, and nanoparticles, have been derived by varying molecular weights and casting solvents. Upon examining catalytic current responses of the GOx integrated PFS-PI systems, notably, the morphology of PFS-PI is found out to be a crucial parameter in determining the efficiency of electron transfer. For example, the use of bicontinuous PFS-PI confirms 2-50 times improved catalytic current densities, compared with the values of other morphologies; the maximum catalytic current of glucose oxidation was 0.7 mA/cm(2) at 70 mM glucose concentration. The biosensing ability of the fabricated electrode with structural optimization was also exploited, and good sensitivity is obtained at the physiological concentration of glucose in blood.