Capillary‐assisted bipolar electrochemistry: A focused mini review

Abstract

The cover picture shows the site-selective chemical modification of a carbon microtube (CMT) that travels inside a capillary due to electroosmotic flow. The external electric field, highlighted by the color gradient, is responsible for the polarization established between the solution and the CMT. Cathodic and anodic poles are therefore induced at both ends of the CMT, which behaves as a so-called bipolar electrode. When the capillary solution contains metal ions, metal electrodeposition occurs at the cathodic extremity which is responsible for the symmetry breaking and results in a Janus CMT.

A 30 nm Nanopore Electrode: Facile Fabrication and Direct Insights into the Intrinsic Feature of Single Nanoparticle Collisions

“…Then, the bipolar electrochemical reaction is employed to further promote the growth of solid gold nanotip (Steps II and III, Figure b). Bipolar electrochemistry promotes two electron transfer processes taking place at the terminals of a conductor under the electric field . The only condition to trigger the bipolar electrochemical reaction is a sufficient potential across the conductor, which is higher than the required potentials of a pair of redox reaction at two terminals.…”

“…Once the gold is generated, the filled Au could prevent the further generation of gold from the chemical reaction between AuCl 4 À and BH 4 À .A tt his time,t he generated gold tip might be irregular and erratic,w hich is hard to act as aw elldefined nanoelectrode.T hen, the bipolar electrochemical reaction is employed to further promote the growth of solid gold nanotip (Steps II and III, Figure 1b). [26][27][28][29][30][31] Theo nly condition to trigger the bipolar electrochemical reaction is as ufficient potential across the conductor,w hich is higher than the required potentials of apair of redox reaction at two terminals.U nder a3 00 mV bias potential, AuCl 4 À could be further reduced to continuously form the gold nanotip.Compared with the chemical reaction, it electrochemically prolonged the gold nanotip,w hich ensures that the majority of the potential would drop at the tip,which significantly increases the polarization difference at the two terminals of the tip. [26][27][28][29][30][31] Theo nly condition to trigger the bipolar electrochemical reaction is as ufficient potential across the conductor,w hich is higher than the required potentials of apair of redox reaction at two terminals.U nder a3 00 mV bias potential, AuCl 4 À could be further reduced to continuously form the gold nanotip.Compared with the chemical reaction, it electrochemically prolonged the gold nanotip,w hich ensures that the majority of the potential would drop at the tip,which significantly increases the polarization difference at the two terminals of the tip.…”

Bipolar (Bio)electroanalysis

“…Performing BPE with a CE equipment has several advantages. (28) The first one is due to the high electric fields that can be applied, which is an extremely important parameter for the polarization of small objects. A second very attractive feature is the intrinsic presence of liquid flow, due to the EOF within the capillary.…”

Advances in bipolar electrochemiluminescence for the detection of biorelevant molecular targets

“…Although being well known in specific domains such as corrosion or electrolysis, BPE remained relatively unexplored until the early 2000's when it has been intensively reinvestigated by several groups. BPE has now found a whole range of new applications especially in the fields of materials science and electroanalytical chemistry [1][2][3][4][5][6][7][8].…”