Selective Al3+ and Fe3+ detection using imidazole–oxadiazole sensors: bioimaging evidence from zebrafish

Abstract

This study introduces a novel fluorescent organic material, 4-(1-(4-(5-(furan-2-yl)-1,3,4-oxadiazol-2-yl)phenyl)-1H-phenanthro[9,10-d]imidazol-2-yl)-N,N-diphenylaniline (TIMF), specifically designed for the detection of aluminum (Al³⁺) and iron (Fe³⁺) ions. TIMF exhibits exceptional selectivity, rapid response times, and high effectiveness in complex matrices such as biological fluids and environmental samples. Furthermore, the sensing study was supported by density functional theory (DFT) studies that validate its binding mechanisms. Synthesized with an imidazole–oxadiazole core, TIMF demonstrates low cytotoxicity (14 ± 0.25 μM) and achieves detection limits of 164 nM for Fe³⁺ and 45 nM for Al³⁺ in an aqueous ethanol medium. Both in vitro (MDA-MB-231 cells) and in vivo (zebrafish, Danio rerio) studies show minimal cytotoxicity, facilitating its application in tracing intracellular Al³⁺ ions in zebrafish embryos. TIMF's rapid and selective fluorescence response underscores its suitability for intricate biological and environmental analyses.