Evaluation of portable single-chamber microbial fuel cell using Pichia fermentans for electrochemical sensing of cobalt

The present study investigates the performance of single-chambered microbial fuel cell in the presence and absence of heavy metal (CoCl₂). The developed cell was further evaluated for its potential application in heavy metal sensing based on its electrochemical performance. A portable MFC was fabricated using 3 cm polyethylene tube. Pichia fermentans was used an exoelextrogenic yeast and the electrochemical response of the MFC were examined over 220 min, using varying external resistances ranging from 33 Ω to 1 MΩ. Cobalt chloride solution was added to the cells to assess the impact of heavy metal on MFC performance. Voltage, power density, and current density, cyclic voltammetry at different scan rates were recorded and analyzed to evaluate the sensor's effectiveness. The MFC without metal exhibited a steady increase in voltage over time, peaking at 90 mV at 220 min, with the highest power density and current density observed at lower external resistance. As resistance increased, the power output declined sharply. In contrast, the cobalt chloride-injected system showed a lower voltage of 40 mV under the same experimental conditions. Thus, the study demonstrated that the yeast based portable MFC exhibit excellent sensitivity to environmental contaminants such as cobalt chloride, making them highly suitable for heavy metal biosensing applications.