Dual-responsive Zr(iv) MOF based fluorometric sensor for rapid and selective detection of anti-cancer drug dacarbazine and herbicide oryzalin in environmental and biological samples†

Abstract

The widespread use of pesticides, herbicides, and therapeutic drugs has raised significant concerns due to their potential toxic effects, especially when misused or overused. These contaminants pose risks to both environmental and human health, necessitating the development of highly sensitive and reliable detection methods for their quantitative analysis in wastewater, food, and biological fluids. Existing detection techniques often suffer from limitations such as low sensitivity, slow response times, and interference from other substances present in complex matrices. Therefore, there is a critical need for advanced sensing platforms that can rapidly and selectively detect these harmful compounds with high precision. A luminescent metal–organic framework (MOF) can serve as an efficient fluorometric sensor for detection of toxic analytes. A novel benzofuran based Zr(IV)-MOF-based probe was synthesized and characterized properly. Fluorescence quenching efficiency, detection limits, response time, and selectivity of the MOF towards DCZ and ORZ were evaluated through experimental studies. Additionally, the sensor's real-world applicability was tested in various environmental and biological samples, including serum, urine, and wastewater, under different pH conditions. Computational studies were also performed to elucidate the fluorescence quenching mechanism. The developed fluorometric sensor exhibited remarkable quenching efficiencies of 90% for DCZ and 80% for ORZ which demonstrate high sensitivity with detection limits of 57 nM and 60 nM, respectively. The Stern–Volmer constants (K_SV) were calculated as 1.85 × 10⁵ M⁻¹ for ORZ and 1.52 × 10⁵ M⁻¹ for DCZ, indicating strong analyte interactions. The probe showed a rapid response time of 10 s for both analytes and exhibited excellent selectivity against potential interferents. Thus, this study presents the first fluorometric-based dual probe specifically designed for DCZ and ORZ detection. The sensor's high sensitivity, rapid response, and strong selectivity make it a promising tool for monitoring hazardous analytes in environmental and biological settings. The insights gained from experimental and computational analyses further support the practical utility of this Zr-based MOF sensor in real-world applications.