A Single-Use Paper-Shaped Microbial Fuel Cell for Rapid Aqueous Biosensing

The traditional chamber‐based microbial fuel cell (MFC) often has the disadvantages of high ohmic resistance, large volume requirements, and delayed start‐up. In this study, paper‐shaped MFCs utilizing a porous carbon anode, a solid Ag2O‐coated carbon cathode, and a micrometer‐thin porous polyvinylidene fluoride (PVDF) separator are investigated to address the classical MFC issues. The Ag2O‐coated cathode has a low overpotential of 0.06 V at a reducing current of 1 mA compared to a Pt–air cathode. Rapid inoculation by filtration results in an instantaneous power density of 92 mW m−2 with an internal resistance of 162 Ω. Integrated current over the first 30 min of operation has a linear relation with microbial concentration. Sensing the difference: A paper‐shaped microbial fuel cell has low internal resistance, inoculation by filtration results in instantaneous power generation, and the integrated current is linearly correlated to microorganism concentration. Thus, there is potential for single‐use rapid biosensing.