From lab to field: Supramolecular probe for gossypol real-time quantification

The extensive use of gossypol-containing cottonseed products in food and animal feed presents considerable health hazards to humans and livestock. Despite the pressing demand for rapid and user-friendly detection methods to monitor gossypol contamination, existing solutions are insufficient. To address this critical need, we introduce a novel supramolecular fluorescent probe that exploits the strong binding ability between human albumin serum (HSA) and gossypol for sensitive and selective detection of gossypol in food samples. The probe incorporates a merocyanine-based disaggregation-induced emission (DIE) fluorescent dye MCID, which forms a stable supramolecular MCID@HSA complex upon encapsulation by HSA. Upon introducing gossypol, specific host-guest interactions within the supramolecular probe resulted in a marked fluorescence enhancement at 614 nm. This facilitated the rapid and quantitative detection of gossypol, achieving a detection limit as low as 13.7 nM and a rapid response time of 10 s. The probe demonstrated excellent selectivity and anti-interference capabilities, ensuring reliable performance in complex matrices. We further engineered this technology into a smartphone-based colorimetric detection system for gossypol detection. This approach obviates the need for expensive instrumentation, providing an accessible alternative for gossypol quantification. The supramolecular probe was effectively utilized for the quantification of trace amounts of gossypol in real samples, such as cottonseed oil and cottonseed meal, yielding satisfactory recovery rates and reproducibility. This innovative approach integrates high analytical performance with practical applicability, providing an essential solution for food safety monitoring.