Homoleptic cyclometalated iridium(III) complex nanowires electrogenerated chemiluminescence sensors for high-performance discrimination of proline enantiomers based on the difference of electron-transfer capability

Abstract Chiral molecules can generally exhibit different physiological and biological activities, thus triggering wide interest in chiral discrimination. Herein, we demonstrate a sensitive homoleptic cyclometalated iridium(III) complexes nanowires (Ir(piq) 3 NWs) electrogenerated chemiluminescence (ECL) sensor for high-performance discrimination of chiral molecules based on the difference in electron-transfer ability between different radicals. The developed Ir(piq) 3 NWs/ITO sensor exhibits high ECL signal and satisfying stability without the presence of co-reactant based on hot electron-induced ECL, which would spur its further application in detecting proline enantiomers. Obvious difference on the ECL intensity towards L -Pro and D -Pro is observed under the presence of high concentration of proline enantiomers, which attributes to the different electron-transfer capability between Ir + (piq) 3 and L -pro • / D -pro • . In order to attain high-performance discrimination, we construct the Ir(piq) 3 NWs/TPrA sensor to achieve chiral discrimination for trace amounts of proline enantiomers (1.0 × 10 −9 M), which attributes to the strong molecular interactions enhanced by introduction of active radical TPrA • .