Application of microfluidic chip coupled with carbon dots-MOF-enriched chromogenic membrane in the detection of various perfluorinated compounds.

Perfluorinated compounds (PFCs), due to their persistence, toxicity, and bioaccumulation, pose significant environmental and public health concerns. However, their low concentrations and the complexity of environmental matrices present major analytical challenges. In this study, we developed a carbon quantum dot-based fluorescent sensing array integrated with membrane enrichment technology for the sensitive and selective detection of three representative PFCs: PFOA, PFOS, and PPVE. Three types of carbon quantum dots with distinct surface functionalities were synthesized, enabling differential fluorescence quenching upon interaction with target analytes. To improve detection sensitivity and reduce matrix effects, a membrane-based enrichment strategy was employed, allowing selective preconcentration and visible signal generation on the membrane surface. The platform achieved detection limits as low as 0.33, 0.35, and 0.40 μM for PFOA, PFOS, and PPVE, respectively. Multivariate analysis using linear discriminant analysis (LDA) and hierarchical agglomerative clustering (HAC) enabled clear discrimination of the three PFCs. The method was successfully applied to real water samples, achieving identification accuracies of 95.82 %, 93.23 %, and 90.48 % in tap, river, and lake water, respectively.