Bipotentiostats

A bipotentiostat is an electrochemical instrument capable of controlling the potentials between three electrodes simultaneously. Unlike a standard potentiostat which controls the potential between two electrodes (working and counter), a bipotentiostat adds a third electrode, often referred to as a "reference electrode 2" or "auxiliary electrode." This allows for the independent control of potential at two different interfaces within the same electrochemical cell.

The primary application of bipotentiostats lies in studying systems involving multiple electroactive species or coupled electrochemical reactions. A common use is in the investigation of redox enzymes immobilized on electrodes. In such setups, one potential is applied to a working electrode modified with the enzyme, while a second potential is applied to a second working electrode, which may be the counter electrode or another distinct working electrode. This enables the simultaneous control of the enzyme's redox state and the conditions at another electrochemical interface.

Bipotentiostats are also employed in studying diffusion-limited currents at multiple electrodes, analyzing coupled redox processes, and investigating the behavior of electrocatalysts in complex reaction pathways. The ability to precisely control potentials at two distinct points within an electrochemical system provides researchers with greater flexibility and insight into intricate electrochemical phenomena. The instrument typically consists of two independent potentiostat circuits integrated into a single unit, each capable of controlling a specific electrode pair relative to a shared or separate reference electrode.