Julolidine-hydrazide-based D-?-A fluorescent chemoprobes for detection of Al3+ and Differentiation of Arsenic species: Applications in portable test strips, ecological assessment, and DFT studies

Abstract

In this study, a novel donor-?-acceptor (D-?-A) chemoprobe was synthesized using julolidine and hydrazide derivatives. The probes S1R1 and S1R2 demonstrated promising capabilities in sensing Al3+ and AsO<inf>2</inf>- ions through fluorescence. Specifically, probes S1R1 and S1R2 exhibited selectivity towards detecting Al3+ ions, with detection limits of 0.0485 ppm and 0.1754 ppm, respectively. These probes were effectively applied in environmental monitoring for detecting Al3+ ions in various samples, including natural water, soil, pharmaceutical tablets, and E.coli cells, and also a portable test strip for the easy detection of Al3+ ions. Moreover, probe S1R2 showed discriminative detection of AsO<inf>2</inf>- over AsO<inf>4</inf>3- ions in semi-aqueous media, with a detection limit of 0.1055 ppm. This discrimination ability is attributed to the lower hydration energy of AsO<inf>2</inf>- ions compared to AsO<inf>4</inf>3- ions, enabling preferential binding to S1R2. The observed turn-on fluorescence performance of probes S1R1 and S1R2 upon the addition of Al3+ ions are attributed to the chelation-enhanced fluorescence (CHEF) phenomenon. Additionally, live cell imaging experiments demonstrated that probes S1R1 and S1R2 can effectively detect Al3+ ions within E.coli cells using a Cell imaging reader. © 2024 Elsevier B.V.