An imidazole functionalized aqua-stable metal–organic framework for selective fluorogenic detection of herbicide DNOC and antibacterial agent furaltadone in various biological and environmental specimens

Abstract

The widespread use of herbicides like dinitro-o-cresol (DNOC) and veterinary drugs such as furaltadone (FLT) has surged to meet agricultural and animal husbandry demands, raising significant health and environmental concerns due to their extensive use and unregulated disposal. To address this issue, herein, we developed an imidazole-functionalized metal–organic framework (MOF)-based fluorometric dual sensor for rapid and selective detection of these analytes in aqueous medium. The present MOF-based probe demonstrated 82% fluorescence quenching upon DNOC introduction, whereas 89% quenching occurred in the presence of FLT. The probe exhibited notably high sensitivity, with the lowest ever reported limit of detection (LOD) of 0.5 nM for DNOC and 1.1 nM for FLT. The highest reported Stern–Volmer quenching constant (K_SV) value of 5 × 10⁷ M⁻¹ and 2 × 10⁷ M⁻¹ for DNOC and FLT, respectively, further indicates the extraordinary sensitivity of the sensor towards these targeted analytes. The MOF showed a rapid response time of 5 s for both DNOC and FLT. The sensor also demonstrated outstanding selectivity even in the presence of interfering substances, proving effective in various complex environments such as serum, urine, wastewater, and different pH media. We thoroughly investigated the sensor's working mechanisms using different advanced analytical techniques to understand its high selectivity towards the targeted analytes. These findings underscore the sensor's practical and potential real-world applications, offering a valuable tool for environmental pollution monitoring and public health protection.