Fast and sensitive detection of highly toxic thiophenol using β-CD modified nanofibers membrane with promoted fluorescence response

Thiophenols are widely used in chemical and pharmaceutical industries , but the acute toxicity and irritating effects of these chemicals pose a threat to public health. A nanofibrous membrane-based fluorescent and colorimetric sensor was synthesized for the convenient and portable detection of thiophenols relying on the nucleophilic substitution reaction of chlorinated dipyrrole fluoride (BODIPY). To improve the sensing efficiency, β-CD was introduced as an addictive to regulate the molecular structure and physicochemical properties of the substrate membrane. The result showed that β-CD with appropriate cavity had good capability for complexing with the probe BODIPY, which successfully reduced the leakage of BODIPY during used. Also, thiophenol could be enriched by β-CD, and enhanced ratiometric fluorescence responses were achieved. The improved hydrophilicity facilitated the full contact of the NFM with thiophenol, contributing to a fast and efficient sensing process.The sensor system achieves a much shorter response time (180 s) and an extremely lower detection limit (0.11 nM). Furthermore, the sensor's fluorescent color changes can be identified by naked eye, showing great promise for the real-time on-site monitoring of thiophenols in both water and gas phases. Possible sensing mechanisms were investigated through theoretical calculation. Practical feasibility was validated through the actual sample analysis.