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

Abstract

• A Con A/AuNPs/CC electrode was facilely fabricated and used as novel anode material. • The interactions between Con A and bacterial lipopolysaccharide enable fast bacteria inoculation. • The interactions between Con A and bacterial lipopolysaccharide increase the bacterial loading capacity. • The proposed MFC can produce a maximal power density of 3362 mW cm -2 . • The MFC is used as a self-powered biosensor for heavy metal toxicity detection. 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 Hg 2+ 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 Hg 2+ concentration from 0.2 to 3 ppm, with a low detection limit of 0.05 ppm.