In-situ self-assembled integrated capture-detection platform based on cuttlebone-derived organic matrix for sensitive...

Owing to their small size and high specific surface area, nanoplastics (NPs) exhibit strong adsorption capacity, making them major carriers of pollutants in the environment. Efficient capture and accurate detection of NPs remain formidable challenges. Therefore, an integrated biomass-based surface-enhanced Raman scattering (SERS) platform was developed using a renewable and eco-friendly cuttlebone-derived organic matrix (CDOM). Abundant functional groups on CDOM captured polystyrene (PS) NPs through physical interception, electrostatic interaction, and hydrogen bonding. In-situ immobilization of silver nanoparticles (AgNPs) generated PS@AgNPs-CDOM with high-density SERS hotspots, which enabled the detection of PS, poly(methyl methacrylate), and polyethylene terephthalate NPs without prefabricated substrates. The capture mechanisms were explored via kinetic model, isothermal adsorption model, and thermodynamic model, while finite element simulation clarified the SERS enhancement mechanisms. The method achieved the lowest detectable concentration of 10^-7 mg/mL for PS NPs in spiked seawater samples, with recoveries above 90.49% and the relative standard deviation values below 18.19%. This platform was successfully applied to the capture and detection of PS NPs in real seawater matrices. More importantly, this study provided a novel, green, and efficient strategy for the integrated in-situ capture and detection of NPs in diverse aquatic environments.