Electrogenerated Chemiluminescent Chemodosimeter Based on a Cyclometalated Iridium(III) Complex for Sensitive Detection of Thiophenol

Abstract

Thiophenol is the simplest aromatic thiol that is utilized for various applications in industry and agriculture. However, it should be used with care because thiophenol is readily absorbed into the human body by inhalation and ingestion, which leads to serious internal injuries. Thus, there is an urgent need for real-time and accurate monitoring of thiophenol. Despite remarkable advantages of electrogenerated chemiluminescence (ECL) analysis, ECL thiophenol probes have never been reported. Herein, a new strategy for the rapid detection of thiophenol by use of an ECL turn-on chemodosimeter based on a cyclometalated Ir(III) complex is described. This analytical system showed superior sensitivity [limit of detection (LOD) value, 3.8 nM] in comparison to the conventional fluorescence method. In addition, our system exhibited remarkable selectivity and reaction rate toward thiophenol over other analytes. Moreover, it was successfully applied to quantify thiophenol in real water samples, providing a new proof-of-concept for field monitoring based on ECL.

Recent Progress in the Development of Fluorescent Probes for Thiophenol

“…Among them, transition-metal complexes (i.e., Ru, Ir, and Os) are particularly attractive because of their wide variety of structures and photophysics properties. Using 1-phenylisoquinoline/4′-formyl-1-phenylisoquinoline and acetylacetone as the ligands, Hong et al developed two cyclometalated iridium(III) complexes ( 57 , 58 ) as both photoluminescence (PL) and ECL probes for sensing PhSH [137]. The structures and ECL sensing mechanisms of these probes are shown in Figure 24.…”

“…( b ) Electrochemiluminescence (ECL) sensing mechanism of probe 58 for PhSH. Reproduced with permission from Reference [137]; copyright American Chemical Society.…”

PEGylation Improved Electrochemiluminescence Supramolecular Assembly of Iridium(III) Complexes in Apoferritin for Immunoassays Using 2D/2D MXene/TiO2 Hybrids as Signal Amplifiers

“…Electrochemiluminescence (ECL) as an electrochemically triggered luminescence technique has received continuously growing scientific interest owing to its merits of high sensitivity, simplicity of operation, and excellent spatiotemporal control on light emission . To date, the ECL technique has been researched in depth with wide application extension in real-time health monitoring, point-of-care diagnosis, and sandwich-type immunoassays. , Besides the tris­(2,2′-bipyridine)­ruthenium­(II) [Ru­(bpy) 3 2+ ]-centered sensing paradigm accompanied by tri- n -propylamine (TPrA), various interesting ECL-active iridium­(III) complexes recently arose to gain significant momentum triggered by the need for diverse emitters with high efficiency. , Iridium­(III) complexes have high quantum efficiencies, long luminescence lifetimes, tunable emission wavelengths, and high thermal and electrochemical stabilities. , They have been recently applied for sensitive analysis of nucleic acids and aromatic molecules, as well as biomarkers by constructing ECL devices that can rapidly quantify the contents of the target. − As previously reported, the cyclometalated iridium­(III) complex of bis­(2-phenylpyridinato)­acetylacetonate [Ir­(ppy) 2 (acac)] can exhibit comparable ECL efficiency with the elegant Ru­(bpy) 3 2+ /TPrA standard . Nevertheless, the water-insolubility of Ir­(ppy) 2 (acac) restricted its application in biosensing.…”

Photocatalytic Unsymmetrical Coupling of 2-Substituted Quinolines: Synthesis and Evaluation of the Antiplasmodial Potential of β-Norbenzomorphan Frameworks

“…Quinoline and its derivatives are among the important heterocyclic compounds . In the development of medicines and pesticides, quinoline motifs are highly important owing to their potential physiological properties such as antimalarial, antitumor, antioxidant, antiproliferative activities, and so forth. − Substituted quinolines are commonly faced in natural products, medicinal chemistry, and material chemistry. − Beside this, quinoline-based compounds are also used as an intermediate in the total synthesis for designing various important synthetic compounds . Accordingly, many transition-metal-catalyzed C–H activation/functionalization methods have been explored including alkylation/alkenylation/arylation, − amidation, , nitration, and halogenation at different positions of the quinoline moiety.…”