Potential Control of a Single Open Bipolar Electrode in an Array Device Using an Ion-Selective Electrode and Ag/AgCl Electrode (Supporting Information)

An electrochemical circuit containing a control unit is used to control the interfacial potential difference between the bipolar electrodes (BPEs) and the electrolyte solution in an open bipolar system. The control unit consists of a polymeric Na+ ion-selective electrode (ISE) connected to a BPE and an Ag/AgCl wire, which connects the electrolyte solution in the control unit to the main chamber via the BPEs. The BPEs contain openings with exposed platinum areas, which serve as cathodic and anodic poles and a potential-determining element. The interfacial potential difference between the potential-determining opening (PDO) and the electrolyte solution can be determined by applying Kirchhoff's second law to the closed circuit containing the PDO, ISE, and Ag/AgCl wire. In the open bipolar system, the intensity of the electrochemiluminescence signal measured for analysis varies depending on the position of the opening of the BPEs. The results suggest that the interfacial potential difference between the anodic and cathodic poles can be varied with a control unit by avoiding ionic crosstalk.