Conductive Gels Based on Modified Agarose Embedded with Gold Nanoparticles and their Application as a Conducting Support for Shewanella Oneidensis MR‐1

Abstract

AbstractShewanella oneidensis is an electrogenic microbe which could be more widely applied in biosensing and fuel cell applications if better methods existed to promote electrode‐biofilm formation. This paper reports a simple procedure that converts agarose, a cheap and readily available polymer, into a modified “MAgarose” material which will form biocompatible hydrogels that embed gold nanoparticles (AuNPs) along the fibers to yield a composite material with a conductivity ca. 80 times higher than an unmodified agarose‐AuNP gel. Proof‐of‐concept bioelectrochemical experiments using Shewanella oneidensis show that when these MAgarose‐AuNP gels are used to coat carbon veil there is a 10‐fold increase in oxidative microbial current production when tested in a 3‐electrode cell set‐up. Microscopy results show that this can be attributed to the ability of the composite hydrogel to support MR‐1 growth throughout the 3D matrix.