Wireless Imaging of Transient Redox Activity Based on Bipolar Light-Emitting Electrode Arrays

Abstract

Bipolar electrochemistry (BE) is a wireless electrochemical technique, which enables asymmetric electroactivity on the surface of conducting objects. This technique has been extensively studied for different electrochemical applications, including synthesis, separation, sensing, and surface modification. Here, we employ BE for imaging the transient electrochemical activity of different redox species with high accuracy via an array of light-emitting diodes having different lengths. Such a gradient allows the differentiation of redox systems due to their intrinsic difference in thermodynamic potential and the evaluation of their diffusional behavior based on the intensity of light emission. The result is an instantaneous optical readout of analytical information, equivalent to classic electrochemical scanning techniques, such as linear sweep voltammetry.

Wireless Light‐Emitting Electrode Arrays for the Evaluation of Electrocatalytic Activity

“…Thus, the physico-chemical information of the coupled redox reactions is directly encoded by the current passing through the LED and its concomitant light emission intensity. [40,41] The synergy between BE and this type of microelectronic light emitting devices has been studied in order to design multiple unconventional electroanalysis platforms, [42] allowing the quantification of species ranging from organic molecules [43,44] to ions [45][46][47] and enantiomers. [48,49] Herein, we take advantage of such wireless light-emitting devices to study the synergetic effect of the composition of the anode and cathode of an electrolyzer on its electrocatalytic activity towards water splitting.…”

Wireless Multimodal Light‐Emitting Arrays Operating on the Principles of LEDs and ECL

“…[1][2][3][4] These devices take advantage of the current or voltage generated during an interfacial electron transfer in order to trigger light emission either by fluorescence, [5][6][7] electrochemiluminescence (ECL), [8][9][10][11][12][13][14] or by using light-emitting diodes (LEDs). [15][16][17][18][19][20] Thus, the physicochemical information is encoded in the corresponding flux of electrons across the electrochemical device and its light emission. Such systems enable interesting applications from sensing to optical mapping/imaging.…”

“…Electrochemically driven light‐emitting systems have gained considerable attention as optical platforms for the study of physico‐chemical information [1–4] . These devices take advantage of the current or voltage generated during an interfacial electron transfer in order to trigger light emission either by fluorescence, [5–7] electrochemiluminescence (ECL), [8–14] or by using light‐emitting diodes (LEDs) [15–20] . Thus, the physicochemical information is encoded in the corresponding flux of electrons across the electrochemical device and its light emission.…”

Complex electrochemiluminescence patterns shaped by hydrodynamics at a rotating bipolar electrode

“…[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), fluorescent probes or electrochemiluminescence (ECL) reactions. [5][6][7][8][9][10][11][12][13][14] In particular, the latter has become a powerful tool in optical imaging, due to its high sensitivity, broad dynamic range, fast response time and low cost of analysis. [15][16][17] Briefly, by applying a potential step, a sequence of reactions is initiated by electrogenerated species in order to populate the excited state of a luminophore, which emits light upon relaxation.…”