Abstract
Electrochemiluminescence (ECL) imaging analysis based on the ultra-high-density microwell electrode array (UMEA) has been successfully used in biosensing and diagnostics, while the studies of ECL generation mechanisms with spatial resolution remain scarce. Herein we fabricate a gold-coated polydimethylsiloxane (PDMS) UMEA using electroless deposition method for the visualization of ECL reaction process at the single microwell level in conjunction with using microscopic ECL imaging technique, demonstrating that the microwell gold walls are indeed capable of enhancing the ECL generation. For the classical ECL system involving tris(2,2′-bipyridyl)ruthenium (Ru(bpy)3 2+) and tri-n-propylamine (TPrA), the ECL image of a single microwell appears as a surface-confined ring, indicating the ECL intensity generated inside the well is much stronger than that on the top surface of UMEA. Moreover, at a low concentration of Ru(bpy)3 2+, the ECL image remains to be ring-shaped with the increase of exposure time, because of the limited lifetime of TPrA radical cations TPrA+•. In combination with the theoretical simulation, the ring-shaped ECL image is resolved to originate from the superposition effect of the mass diffusion fields at both microwell wall and bottom surfaces.
Highlights
Electrochemiluminescence (ECL) is light emission from excited state luminophores generated by electrochemical reactions, which possesses better spatiotemporal control in comparison with chemiluminescence (Richter, 2004; Hu and Xu, 2010; Hesari and Ding, 2017; Liu et al, 2019)
We have reported the measurement of the thickness of ECL-emitting layer using microtube electrode ensembles, showing that the combined use of microelectrode ensembles and ECL imaging technique is a powerful tool for deciphering ECL reaction mechanisms (Guo et al, 2020)
We further investigate the evolution of ECL rings with the exposure time of electron multiplying charge coupled device (EMCCD), and the potential was pulsed to optimized value of 1.0 V
Summary
Electrochemiluminescence (ECL) is light emission from excited state luminophores generated by electrochemical reactions, which possesses better spatiotemporal control in comparison with chemiluminescence (Richter, 2004; Hu and Xu, 2010; Hesari and Ding, 2017; Liu et al, 2019). Confined Electrochemiluminescence Generation at Microwells structures at the single entity level (Xu et al, 2012; Xu et al, 2014; Valenti et al, 2017; Ma et al, 2018; Voci et al, 2018; Zhu et al, 2018; Ding et al, 2020; Zhang et al, 2020). ECL imaging provides an addressable approach to map the spatial distribution of ECL generation on a single bead surface, proving the existence of low oxidation potential route for ECL generation (Sentic et al, 2014; Dutta et al, 2020)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
