Imidazole‐Centred Oxadiazole Sensor for Detecting Al³⁺ and Fe³⁺ Cations in Living Cells: A Zebrafish Bioimaging Approach

ABSTRACT This study introduces a novel organic fluorescent chemosensor, designated as imidazole 4‐(1‐(4‐(5‐(4‐( tert ‐butyl)phenyl)‐1,3,4‐oxadiazol‐2‐yl)phenyl)‐1 H ‐phenanthro[9,10‐ d ]imidazol‐2‐yl)‐N,N‐diphenylaniline ( TIMTB ). Engineered specifically for detecting aluminium (Al 3+ ) and iron (Fe 3+ ) ions, TIMTB demonstrates exceptional selectivity, rapid response times, and efficacy in complex matrices such as biological fluids and environmental samples. Comprehensive evaluations through UV absorption, fluorescence spectroscopy, and pH‐dependent studies confirm TIMTB 's high sensitivity and selectivity towards Al 3+ and Fe 3+ . Further, the study was supported by Density Functional Theory (DFT) studies. TIMTB , synthesized with an imidazole‐oxadiazole core, exhibited significantly low cytotoxicity (14 ± 0.15 μM). In aqueous ethanol medium, the probe achieved notably low detection limits of 2 nM for Fe 3+ and 2.19 μM for Al 3+ . Minimal cytotoxicity was observed in both in‐vitro (MDA‐MB‐231 cells) and in‐vivo (zebrafish, Danio rerio ) studies, paving the way for its application in tracing intracellular Al 3+ ions in zebrafish embryos. TIMTB 's robust performance underscores its potential as an invaluable tool for environmental monitoring and biomedical applications.