Galvanic Bipolar Electrode Arrays with Self-Driven Optical Readouts

Abstract

In this work, we report a bipolar electrode (BPE) array system with self-driven optical readouts of the faradic current flowing through the BPEs. The BPE array system is based on the spontaneous redox reactions that are respectively occurring at opposite poles of the BPEs with appropriate electrocatalysts on the poles; this system is analogous to one consisting of galvanic electrochemical cells. The galvanic BPE array system operates in a self-powered mode that requires there to be neither a direct electrical connection nor external electrical polarization to each BPE. Importantly, the appropriate electrocatalysts on the poles play a critical role in the galvanic BPE array system to induce the spontaneous redox reactions occurring at the poles of BPEs. Moreover, the galvanic BPE array system provides self-driven optical readouts, including fluorometric and colorimetric ones, to report the faradaic current resulting from the spontaneous redox reactions on the BPE poles. Based on the unique benefits that the galvanic BPE array system has over conventional BPEs, we demonstrated the promising potential of galvanic BPE arrays for the simple yet rapid and quantitative screening of electrocatalysts for the oxygen reduction reaction as well as sensitive sensing of H 2 O 2 in parallel.

Complex electrochemiluminescence patterns shaped by hydrodynamics at a rotating bipolar electrode

“…Optical analysis of electrochemical processes using lightemitting systems has gained considerable attention since it offers an easy and straightforward alternative to conventional methods. [1][2][3][4] Commonly, light emission approaches are based on the coupling of chemical processes to microelectronic devices (such as light emitting diodes for example), uorescent probes or electrochemiluminescence (ECL) reactions. [5][6][7][8][9][10][11][12][13][14] In particular, ECL has become a powerful tool in optical imaging, due to its high sensitivity, broad dynamic range, fast response time and low cost of analysis.…”