Hierarchical Ag-ZIF-67 carbon cloth for integrated nanoplastics filtration and sensing

Hierarchically engineered multifunctional materials that integrate efficient separation and ultrasensitive detection within a scalable architecture remain critically needed for practical environmental health monitoring. Here, we report a scale-like Ag-zeolitic imidazolate framework-67 (Ag-ZIF-67) architecture pseudomorphically grown on flexible carbon cloth, enabling simultaneous nanoplastic filtration and molecular sensing. Conformal metal-organic framework (MOF) nanosheets and plasmonic Ag nanoparticles are spatially organized to generate uniform plasmonic coupling and homogeneous electromagnetic hotspots, resulting in excellent signal reproducibility (RSD 3.41%) and a high surface-enhanced Raman scattering (SERS) enhancement factor (1.14 × 10⁸), as validated using 4-mercaptobenzoic acid. Beyond signal amplification, the hierarchical Ag-ZIF-67 carbon cloth functions as an integrated platform that combines structural filtration, selective adsorption, and in situ SERS sensing within a single flexible substrate. This multifunctionality enables trace-level detection, quantitative discrimination, and accurate classification of representative nanoplastics (polystyrene, polymethyl methacrylate, polyethylene, and polyethylene terephthalate), even in spectrally complex mixtures. Detection of polystyrene is achievable down to an ultralow concentration of 0.01 ppm, with reliable quantification demonstrated in mineral, tap, and lake water (recoveries: 95.7-102.3%). This study establishes a scalable multifunctional platform that unifies separation and molecular sensing, providing a practical route toward on-site nanoplastic monitoring and advanced environmental analysis.