Diffusion-based extracellular electron transfer

EAB processes are an interfacial phenomenon EABs interact with the electrode inside the biofilm diffusive and reactive layers at the electrode surface. Extracellular electron transfer is directly related to these microscale layers, whereas diffusion processes above these layers are linked indirectly. Thus, we expect that the surface concentrations of the redox-active compounds and the local solution properties inside EABs are more relevant and critical than the corresponding values in the bulk. Correlating and fitting lines to bulk data may have little significance to the fundamental processes occurring inside EABs. Direct measurements inside EABs are preferred, such as measuring pH inside EABs or measuring the spectroelectrochemical properties of EABs [66, 138, 147]. This is especially important because the cell density inside some EABs is not uniformly distributed and predictions based on simple diffusion may not apply [120]. 

---