Precisely designed oxazolonaphthoimidazo[1,2-a]pyridine-based sensor for the detection of Fe3+ and DCP with cell imaging application

Abstract

Two new turn-off fluorescent sensors (V3 and V4) presented in the article revealed the potential application for the precise detection of Fe3+ and diethylchlorophosphate (DCP). These sensors include oxazolonaphthoimidazo[1,2-a]pyridine scaffold integrated with anthracene and pyrene-based framework. This design has facilitated the twisted intramolecular charge transfer (TICT) and planarised intramolecular charge transfer (PLICT) mechanisms, which were confirmed using computational and photophysical studies. The V3 and V4 fluorescent probes were particularly sensitive and highly selective for detecting Fe3+ and DCP analytes. For Fe3+, V3 and V4 undergo turn-off mechanism with the detection limit of 14.1 and 4.5 nM, respectively. Intracellular detection of Fe3+via confocal live cell imaging was also demonstrated, showing its application under intracellular conditions. Our experimental data revealed the promises of V3 and V4 for instantaneous, accurate and on-spot monitoring of Fe3+ and DCP, even in the presence of other interfering analytes.