Dietary intake is an important exposure pathway of environmental bisphenols including bisphenol S (BPS, a typical emerging organic pollutant). However, available data on the occurrence and risk assessment of BPS in food samples are limited due to the lack of high-throughput analytical methods. Herein, based on H 2 O 2 inducing fluorescence turn-off signals, a sensitive and high-throughput fluorescence enzyme-linked immunosorbent assay (FELISA) was developed for BPS investigation in beverages. In this system, the fluorescence of copper nanoclusters in ZIF-8 (CuNCs-CS@ZIF-8) could be quenched with the presence of H 2 O 2 owing to the strong oxidation, being served as signal amplification in FELISA. Meanwhile, the aggregation-induced emission (AIE) fluorescence enhancement of CuNCs-CS through the conformational locking of ZIF-8 provided an effective strategy to overcome the intrinsic limitations of FELISA including high background, serious fluorescence quenching in the detection of real samples. Thus, the integration of AIE building blocks into porous ZIF-8 showed obvious advantages in enhancing the analytical performance of FELISA. Under optimized conditions, satisfactory results with good accuracy were achieved in this proposed FELISA, which was applied for the systematic investigation of BPS in foods and further health risk assessments. The results after 100 beverages analysis displayed an average detection frequency of 55%, and the detected concentration of BPS ranged from below the limit of quantification (LOQ) to 12.08 ng/mL with a mean value of 1.717 ng/mL. Besides, the estimated daily intake (EDI) of BPS was calculated to be 0.05449–4.483 ng/kg-bw/day, in which milk–tea drinks contributed to the majority of BPS daily intake (mean EDI = 4.483 ng/kg-bw/day). And the hazard quotient (HQ) according to EDI values indicated that BPS exposure in beverages might not make a considerable impact on human health.
As novel energy level-tunable photocatalysts, copper nanoclusters (CuNCs) have been used for combining with conventional catalysts to synergize enhanced the catalytic capabilities. However, conventional photocatalysts have their own drawbacks. In particular, their fixed energy levels are unfavorable for regulating the energy level structure of composite catalysts. In this study, a novel nanoplatform (CuNCs@CS/MOF) was constructed for the detection and photocatalytic degradation of MBT. The chitosan-modified CuNCs were encapsulated within the MOF matrix. The CuNCs maintained an aggregated state and the rotation of their ligands was restricted, thereby further enhancing the photoluminescence intensity and photostability of CuNCs. When exposed to light irradiation, CuNCs@CS/MOF showed remarkable photocatalytic activity, and the underlying mechanism governing the photocatalytic degradation process was elaborated in detail. Specifically, CuNCs@CS/MOF generated photogenerated electrons and holes, the photogenerated electrons reacted with H 2 O 2 to produce ·OH, while the remaining holes accepted electrons donated by MBT. The generated ROS oxidized TMB to oxidized TMB (oxTMB) under light irradiation, which was thereafter diminished by MBT. On this basis, the quantitative detection of MBT was established. Furthermore, ROS could oxidize and decompose MBT into small-molecule fragments, thus achieving the efficient elimination of MBT. This work provides an attractive strategy for designing multifunctional novel nanoplatform, which can be applied for the accurate detection and further harmless treatment of pollutants.
危险品化学品经营许可证（带存储）