Nanoconfined 3D redox capacitor-based electrochemical sensor for ultrasensitive monitoring of metabolites in bacterial communication

Abstract

The ability to monitor metabolites related to cell communication is important for understanding bacterial physiology, identifying bacterial species in a cellular community, and providing insights into the stage of infection. Here, we developed a nanostructured electrochemical sensor comprising a 3D-redox-capacitor-coated electrode, which was prepared by grafting a redox capacitor molecule, catechol/o-quinone, at high density to a chitosan layer. It provided high sensitivity in detecting redox-active bacterial metabolites through a redox cycling reaction in the nanoconfined structures of the electrode. We used it to monitor the secretion of signalling-related metabolites at different growth phases of Pseudomonas aeruginosa. We also used the electrode to detect signalling-related metabolites in diverse simulated body fluids mixed with P. aeruginosa culture. It was able to provide information on bacterial communication and help in sensitive diagnostic monitoring of bacterial infection.