Enzyme Cascade for Catalyzing Sucrose Oxidation in a Biofuel Cell

Monday, May 12, 2014: 09:20
Floridian Ballroom G, Lobby Level (Hilton Orlando Bonnet Creek)
D. P. Hickey (University of Oklahoma), F. Giroud (University of Utah), D. W. Schmidtke, D. T. Glatzhofer (University of Oklahoma), and S. D. Minteer (University of Utah)
Biofuel cells provide a safe and renewable means of powering small electronic devices. We have recently demonstrated a bioanode that is capable of extracting four electrons from a single molecule of sucrose by way of a three-enzyme cascade.  Invertase, fructose dehydrogenase and glucose oxidase are immobilized in a ferrocene-modified linear poly(ethylenimine) (LPEI) hydrogel onto the surface of a carbon electrode.  Fuel sources are generated in the polymer film by (1) hydrolyzing sucrose into fructose and glucose, and then (2) electroenzymatically oxidizing fructose and glucose to produce a current response.  A previously unreported synergistic effect is observed between glucose oxidase and fructose dehydrogenase that results in a current response that is considerably higher than expected.  The newly described enzyme cascade generated 302 ± 57 μA/cm2 at 25 oC and 602 ± 62 μA/cm2 at 37 oC and when poised against an air breathing platinum cathode in a biofuel cell, the multienzyme-containing film generated 42 ± 15 μW/cm2 at 172 mV with a maximum current density of 344 ± 25 μA/cm2 in 100 mmol/L sucrose at 25 oC.