Modified hydrogel for high efficiency SERS detection and adsorption removal of microplastics

In recent years, the problem of microplastics (MPs) pollution has become increasingly serious, and there is an urgent need to develop highly sensitive and efficient microplastic detection and adsorption technologies. Based on surface-enhanced Raman scattering (SERS) technology, a new type of modified hydrogel (M-Hydrogel) substrate was prepared by compounding chitosan, polydopamine and polyvinyl alcohol with nano-silver as the enhancing unit. Taking polyvinyl chloride, polymethyl methacrylate and polyvinylidene fluoride as typical MPs, the adsorption behavior and mechanism of M-Hydrogel on MPs were systematically studied, and the surface morphology, chemical composition and thermal stability of M-Hydrogel were revealed through characterization and analysis. The experimental results show that the adsorption capacity of M-Hydrogel for the same MPs in different actual water bodies does not change much. After six cycles, the adsorption capacity for MPs decreases by less than 46%. Further single-component and mixed sample detection experiments were conducted to verify the high sensitivity and selectivity of M-Hydrogel combined with micro-Raman spectroscopy in the detection of MPs. This study provides a new strategy for the efficient detection and adsorption of MPs in the environment, which has potential practical application value.