Advances in bipolar electrochemiluminescence for the detection of biorelevant molecular targets

Bipolar electrochemistry (BPE) contrasts very much with conventional electrochemistry because it is based on the control of the solution potential instead of the working electrode potential. In a typical setup, a piece of conducting materials is immersed in an electrolyte and submitted to an electric field. Such conditions split the interfacial nature of the materials into cathodic and anodic domains where electrochemical reactions can readily take place. BPE has many potential applications, and the present contribution aims to focus on recent analytical applications that involve electrogenerated chemiluminescence (ECL) detection. ECL is a special case of luminescence where the excited state of the luminophore is populated after a sequence of reaction that is triggered by an initial electron transfer step occurring at the electrode surface. The coupling between BPE and ECL is a powerful approach because it provides a unique opportunity to combine the intrinsic advantages of both techniques. BPE enables the spatial separation of sensing and reporting poles, whereas ECL provides a simple and sensitive visual readout. This opinion article will describe the experimental possibilities and the most recent applications of BPE/ECL coupling for the detection of biorelevant molecular targets.