Development of novel nanostructured electrodes for biological applications

Abstract

This thesis describes the development and testing of a range of electrodes designed to be able to measure electrical current produced by the respiration of bacteria in direct contact with the electrode surface. The electrodes are designed to directly wire into redox processes in the cytoskeleton of the bacteria so that electron transfer can be measured in real time without the need for solution based mediator molecules. The rate of electron transfer from the bacteria is enhanced by nanostructuring the surface of graphite electrodes with vertically aligned single and multiwalled carbon nanotubes (CNTs) and covalently coupling mediator molecules to the CNT tips. A selection of the prepared electrodes are tested with the non-electrogenic bacteria Proteus vulgaris and Bacillus subtilis to demonstrate the potential of the electrode designs to be used with a wide range of microbial species.