Dandelion-like Pd/Cu nanozyme with multi-enzyme activities: A colorimetric sensor array for PFAS discrimination.

Per- and polyfluoroalkyl substances (PFAS) were a class of hazardous contaminants known for their high environmental persistence and toxicity. Due to their strong polarity, wide variety, and broad distribution, a rapid, accurate, and on-site detection method was urgently needed for future screening and emergency response. Herein, a dandelion-like Pd/Cu nanozyme with triple enzyme-like activities (oxidase-like, peroxidase-like, and laccase-like) was synthesized by one-step hydrothermal method. Different PFAS species inhibited these three enzyme-like activities to varying extents. By quantifying absorbance changes, distinct fingerprint patterns were constructed, and a three-channel colorimetric sensor array was developed. This array exhibited high selectivity and robust anti-interference capability for discriminating seven PFAS species. The LDA score plot revealed distinct clustering of different PFAS classes and complex mixtures, indicating clear separability among their fingerprints. The developed nanozyme sensor array was successfully applied to the detection of PFAS in environmental water (river, lake, and tap water). This work provided a novel strategy for selective and reliable detection of PFAS in complex environmental matrices.