Insights Into the Detection Selectivity of Redox and Non-redox Based Probes for the Superoxide Anion Using Coumarin and Chromone as the Fluorophores

Abstract

In this study, we evaluated the applicability of various superoxide anion sensors which were designed based on either redox or non-redox mechanisms. Firstly, both redox- and non–redox-based superoxide anion probes were designed and synthesized using either coumarin or chromone as the fluorophores, and the photophysical properties of these probes were measured. Subsequently, the sensing preference of both types of probes toward various reactive oxygen species (ROS) was evaluated. We found that non–redox-based O2•− probes exhibited broad sensing ability toward various ROS. By contrast, redox based O2•− probes showed a clear reactivity hierarchy which was well correlated to the oxidizing strength of the ROS. Lastly, the detection selectivity of redox-based O2•− recognizing probes was also observed when balancing various factors, such as reactant ROS concentrations, temperature, and changing reaction transformation rates. Herein, we concluded the selectivity advantage of redox-based O2•− probes.

Universal Approach to Direct Spatiotemporal Dynamic In Situ Optical Visualization of On‐Catalyst Water Splitting Electrochemical Processes

“…As another example, hydroethidine‐based fluorophores can be explored for visualizing and probing in‐depth insights on the reactive oxygen intermediates which are known to influence the major energy‐based electrochemical reactions including the oxygen reduction and oxygen evolution reactions. [ 52 , 53 , 54 ] Water splitting is usually carried out under alkaline conditions to catalyze the sluggish oxygen evolution reaction. However, due to the highly corrosive condition under extreme pH, there is a continuous quest to perform the water‐splitting reaction in neutral conditions.…”

Universal Approach to Direct Spatiotemporal Dynamic in-situ Optical Visualization of On-Catalyst Water Splitting Electrochemical Processes

“…At higher flow rates, the curve of the electrolyser's increase in current density reaches a plateau, because of at these high flow rates an effectively fast electrolyte replacement rate is attained, thus effectively inhibiting the formation of the detrimental acidic and basic space fronts at the electrodes vicinity during the water splitting process. including the oxygen reduction and oxygen evolution reactions [55][56][57] .…”