Effect of CuO/ZnO/FTO electrode properties on the performance of a photo-microbial fuel cell sensor for the detection of heavy metals

The development of sustainable, low-cost and responsive technology for heavy metals detection in wastewater is crucial. In this study, by combining CuO/ZnO photocathode with microbial anode, a novel photo-microbial fuel cell (PMFC) sensor was developed. The self-powered PMFC was performed under light and dark condition for heavy metals detection. Compared with MFC sensor, PMFC sensor showed a wider detection range (0.1-4 mg L-1 of Cd2+ and 10-80 mg L-1 of Cu2+). The improved performance in sensing limit and sensitivity was mainly attributed to the intimate P-N heterojunctions formed in CuO/ZnO, which accelerated the electron transport between the photocathode and the microbial anode. Besides, the toxicity of five heavy metals tested in PMFC was shown as Cd2+>Cr6+>Zn2+>Hg2+>Cu2+. This study has taken advantage of the characteristics of PMFC and facilitated its application in heavy metals detection, which provides a new approach for the development of biosensors.

Automated summary

The development of sustainable, low-cost and responsive technology for heavy metals detection in wastewater is crucial. In this study, a novel photo-microbial fuel cell (PMFC) sensor was developed by combining CuO/ZnO photocathode with microbial anode. The PMFC sensor showed a wider detection range and improved sensitivity, attributed to the intimate P-N heterojunctions formed in CuO/ZnO.