Preparation and characterization of biocompatible carbon electrodes

Electron transfer in microbial fuel cell and biosensors could be facilitated through high conductive materials with enhanced active surface area and appropriate redox potential suited to microbial metabolism. In the first strategy based on bulk doping, graphite/epoxy composite electrode (GECE) bulk was modified with six types of metal ion which were prepared through a wet impregnation procedure. In the second strategy, immobilization of redox dye on carbon cloth and graphite sheet was carried out using N,N′-dicyclohexylcarbodiimide for surface modification. Crystallinity, morphology, surface chemistry and electrochemical properties of all modified electrodes were investigated. Influence of redox behavior of electrodes suited to microbial metabolism and conducive to biofilm formation have been examined. It was observed that the Fe3+ doped GECE surfaces exhibited significantly high biofilm formation of 1.10(±0.18) × 107 CFU/cm2 as compared to other dopants. The microbial growth on the carbon cloth electrode and carbon fiber reinforced plate were found to be less (2.6(±0.97) × 104, 4.8(±1.8) × 103 CFU/cm2 respectively) compared to GECEs.