Hydrazone-derived PET/CHEF fluorescent probes for sensitive detection of cesium and strontium in real samples.

Abstract

In this study, two hydrazone-based probes, NSP ((E)-5-(diethylamino)-2-((2-(2,4-dinitrophenyl)hydrazineylidene)methyl)phenol) and NFH ((E)-N'-(4-(diethylamino)-2-hydroxybenzylidene)furan-2-carbohydrazide), were developed and synthesized for the specific detection of Cs+ and Sr2+ ions, respectively. Both probes were very sensitive, with low detection limits of 2.4 nM for Cs+ and 22 nM for Sr2+, along with high selectivity over other metal ions. The binding constant is 4.8 × 107 M-1 for NSP-Cs+ and 6.4 × 105 M-1 for NFH-Sr2+. Job's plot analysis confirmed a 1 : 1 binding stoichiometry between the probes and their corresponding metal ions. The NSP- and NFH-functionalized cotton swabs exhibit excellent stability, highlighting their potential for portable and on-site detection. Complementarily, their efficacy was demonstrated in actual samples, including water, soil, and vegetable matrices, achieving excellent recovery results.