Figure 1.

(A) EF between two electrodes immersed in cell culture, in which the electrodes may take different forms such as L and against the bottom to make the EF more uniform; (B) Using salt bridges between electrodes to avoid the diffusion of electrochemical reaction products into culture medium; (C) Working electrodes as a cell culture substrate in a three-electrode system, where the working electrode can be a metal, a glass slide coated with indium tin oxide, or a conducting polymer.