Characterizing efficiency of multi-Enzyme cascade-based biofuel cells by product analysis

The performance of biofuel cells with enzyme cascades have normally been characterized with open circuit potential, power density, and current density measurements. In this work, we demonstrate that with the method of quantitative product analysis by mass spectrometry, we can obtain other valuable information about the biofuel cell efficiency. Faradaic efficiency, coulombic efficiency and product efficiency were calculated for a six-enzyme glucose biofuel cell system. Oxidation pathway bottlenecks were determined with quantitative mass spectrometry measurements via direct infusion. These measurements and calculations give an in-depth understanding of the bioelectrocatalytic bottlenecks in the enzyme cascade for the target fuel (glucose).