Construction of a high power-density microbial fuel cell based on lipopolysaccharide-lectin interactions and its application for detecting heavy metal toxicity

Herein, we report the short startup time and high power density of a microbial fuel cell (MFC) based on lipopolysaccharide (LPS)-lectin interactions and its application for the detection of heavy metal toxicity. Concanavalin A (Con A) as a typical lectin is immobilized on a carbon cloth (CC) electrode with Au nanoparticles (AuNPs) as the bridge. The interactions between Con A and bacterial LPS can not only accelerate the inoculation speed of Shewanella putrefaciens but also increase the loading capacity of Shewanella putrefaciens on the anode. In addition, AuNPs on the Con A/AuNPs/CC anode can promote the direct extracellular electron transfer. Using the Con A/AuNPs/CC anode, the MFC produces a maximal power density of 3362 ± 120 mW m−2, which is an order of magnitude higher than a CC anode based MFC. Taking Hg2+ as an example, the MFC is used as a self-powered biosensor for toxicity detection in water. The output current density of the MFC decreases linearly with the increase of Hg2+ concentration from 0.2 to 3 ppm, with a low detection limit of 0.05 ppm.