Direct electrochemistry of proteins and enzymes: an introduction

We introduce electrochemistry of redox proteins and enzymes in the context of functional studies. We explain the fundamental concepts of electrochemistry only as far as they are important for understanding at a qualitative level the results that are presented. We have selected the latter to illustrate the variety of mechanistic information that can be gained from electrochemical investigations. We explain the most classical electrochemical experiments, but most results discussed herein were obtained using the con guration called protein lm voltammetry , where the protein is adsorbed onto an electrode surface and electron transfer is direct. We shall not cover all aspects of Faradaic bioelectrochemistry: for example we do not discuss catalytic mediated electrochemistry, the characterisation of the electrode/protein interface in relation to the design of electrodes for immobilizing proteins, and applications in biotechnology (bio-fuel cells, bio-sensors, etc.).