Imaging Analysis Based on Electrogenerated Chemiluminescence

Abstract

Electrochemiluminescence (ECL), also called electrogenerated chemiluminescence, is luminescence that is produced by chemical reactions triggered by electrochemical method. ECL imaging is a novel imaging technique, which can simultaneously provide two kinds of signals of both electrochemistry and optical image. Over the past two decades, ECL imaging has been not only a powerful tool for investigating the fundamental scientific questions such as ECL mechanisms and reaction kinetics, but also a versatile analytical technique for detection of a wide range of analytes including small molecules, DNA, proteins, and cells. In the first part of this review, we briefly describe the reaction mechanisms of ECL generation. Then the review focuses on the research progress on the ECL imaging approach. It is basically introduced from the following five aspects: (i) visualization of electroactive sites on surfaces, (ii) imaging analysis at the single-bead and single-cell levels, (iii) array bioanalysis, (iv) multi-color ECL imaging, and (v) paper chip based on ECL imaging. Finally, some perspectives and future directions in this active research area are presented.

Confined Electrochemiluminescence Generation at Ultra-High-Density Gold Microwell Electrodes

“…Because no external light illumination is required to generate ECL emission, ECL has unique advantages, such as low background and high sensitivity, et al It has manifested itself to be a powerful transduction signal for the determination of small biomolecules, DNA and protein biomarkers in biosensing and clinical diagnostics ( Doeven et al, 2014 ; Wu et al, 2014 ; Lim et al, 2016 ; Bist et al, 2017 ; Ji et al, 2017 ; Yang et al, 2018 ; Zhou et al, 2018 ; Zhang et al, 2019a ; Jones et al, 2020 ). Moreover, ECL has recently emerged as a useful surface analysis technology because of its intrinsic surface-confined and surface-sensitive nature ( Guo et al, 2017 ; Zhang et al, 2019b ; Zanut et al, 2019 ; Ma et al, 2020 ). Compared with the conventional intensity-based ECL measurement of the entire electrochemical ensembles, ECL imaging can function as a diagnostic tool to elucidate the relationship between the topography/structures and electron transfer properties of electrode surface with spatial resolution ( Pantano and Kuhr, 1993 ; Hopper and Kuhr, 1994 ).…”

Towards Determining Kinetics of Annihilation Electrogenerated Chemiluminescence by Concentration-Dependent Luminescent Intensity

“…Important applications of ECL lie in electroanalytical biosensing [2,3], in which antibodies or aptamers are labeled with luminophores to enable a large variety of different assays. In addition, ECL has been extensively investigated for imaging [4,5] as well as light generation [6].…”

“…A * k 4 → A + h , Electronic supplementary material The online version of this article (https ://doi.org/10.1007/s4166 4-019-00094 -z) contains supplementary material, which is available to authorized users.…”

Electrochemistry and Optical Microscopy

“…However, owing to the low efficiency of ECL, the imaging readout did not specifically seek for image resolution but rather for biomarker detection sensitivity. Since they only use electrochemistry as a mean to trigger the luminescence event, imaging-based bioassays are not discussed here; they are comprehensively reviewed [47,198]. The imaging of surface adsorbates by ECL microscopy was proposed in several studies where the fluorophore is either the adsorbate or present in solution.…”