Figure 1.

Schematic illustration of the continuous system and the confined system. (a) The continuous solution is composed of phosphate buffer and potassium chloride. The silver/silver chloride reference electrode and platinum coil counter electrode are in direct contact with the solution. (b) The confined solution is a 1 μL droplet of phosphate buffer and potassium chloride. The droplet is submerged in 1,2-dichloroethane with 0.5 M tetrabutylammonium perchlorate. The platinum coil counter electrode and salt bridge are in direct contact with 1,2-dichloroethane, and the salt bridge connects the reference electrode to the solution. Fi = hexacyanoferrate(III), Fo = hexacyanoferrate(II).