Microbial fuel cell-assisted biogenic synthesis of gold nanoparticles and its application to energy production and hydrogen peroxide detection

This paper reports the simultaneous synthesis of gold nanoparticles (AuNPs) with a spherical and stable structure using microbial fuel cell (MFC) biofilms. The green, facile, chemical stabilizers and capping-agent free AuNPs synthesis allow the binder-free in situ decoration of AuNPs on MFC anode electrode with the help of special interactions of biofilm. The MFC with AuNPs decorated carbon foam anode electrode produced 62.5% higher (46.37 Wm-3) power density than that of the MFC equipped with plain carbon foam anode (control). The AuNPs facilitated the good adhesion of bacteria, amplified the conductivity, and reduced the internal resistance, resulting in improved overall MFC performance. In addition, the peroxide-mimicking activity was evaluated and the MFC-synthesized AuNPs exhibited significantly higher peroxidase mimicking activity than the chemically synthesized AuNPs, thereby, allowing the easy and rapid colorimetric detection of hydrogen peroxide with a detection limit of 20 uM.