Dual-function Anthracene-based fluorescent sensor for antibiotics and iron (III) ion

The Nitrofurans and Fe 3+ ions, are important environmental pollutants whose simultaneous occurrence in aqueous systems is highly problematic from both environmental and human health perspectives. Even though various studies report different fluorescent probes for analysing these pollutants, anthracene-based fluorescent probes for the selective sensing of antibiotics with low detection limit and practical applicability are limited. The exiting literatures revealed that the available chemical sensors are restricted to the detection of only one analyte through a particular mechanism (static or dynamic). Herein, we report the synthesis of a flexible anthracene-based fluorescent probe, 9,10-bis (((1H-benzo [1,2,3] triazol-1-yl) oxy) methyl) anthracene (ANBT) and its application for detection of antibiotics and Fe 3+ . The probe exhibits efficient fluorescence quenching toward Nitrofurantoin (NF), Furazolidone (FZ), and Fe 3+ ions with Stern–Volmer constants of 2.56 × 10 5 , 2.12 × 10 5 , and 9.10 × 10 5 M -1 , respectively, along with low detection limits. Detailed mechanistic investigations reveal that the antibiotic sensing proceeds via dynamic quenching driven by photoinduced electron transfer, whereas Fe 3+ detection occurs through static quenching involving ground-state complex formation. It is important to mention that the probe allows clear differentiation of analytes based on their quenching pathways, providing an additional level of selectivity beyond conventional response-based sensing. The system also demonstrates rapid response, high selectivity, and successful applicability in real water samples.