新型多功能表面增强拉曼散射探针用于微纳塑料海洋生物体内降解行为机制研究

微纳塑料污染是全球第二大海洋环境科学问题，给海洋生态安全造成巨大威胁。微纳塑料可以被多种海洋生物摄取并在体内分布转运，但其体内降解行为和机制的科学认知尚不明朗。本项目拟研发“磁性-表面增强拉曼散射（SERS）-13C同位素”多功能微纳塑料模型粒子，利用降解导致塑料壳层变薄、渗透性提高，引发粒子SERS敏感信号变化的原理，开展基于磁分离和拉曼成像技术的典型海岸带生物体内微纳塑料降解行为评估和机制研究。通过塑料理化性质分析、塑料生物质转化、肠道菌株筛选和体外降解、降解酶以及“真实”塑料降解能力5个方面揭示降解机制，验证SERS评估方法的准确性。在此基础上，总结动物种类、膳食特性和微纳塑料材质、粒径等对降解效率的影响规律。本项目将为微纳塑料的海洋生物降解行为研究提供便捷的分析方法和工具，为海洋塑料污染治理发掘潜在降解物种和菌株资源，为海洋微纳塑料生态效应和最终归趋揭示提供新的研究思路。

Micro-nanoplastic pollution is the second largest scientific problem of marine environment in the world, which poses a great threat to marine ecological security. Micro-nanoplastics can be ingested by a variety of marine animals and distributed and transported in the body, but the scientific understanding of their in vivo degradation behavior and mechanism is still unknown. This project aims to develop multifunctional "magnetic-surface enhanced Raman scattering (SERS)-13C isotope" micro-nanoplastic model particles. Based on the principle that degradation leads to thinning of plastic shell, improvement of permeability and change of SERS sensitive signal of the particles, the plastic degradation behavior and mechanism can be studied in typical coastal animals, based on magnetic separation and Raman imaging technology. The degradation mechanism can be revealed through the analysis of physical and chemical properties of plastics, transformation of plastic to biomass, identification of intestinal bacterial strains and in vitro degradation, degradation enzymes and genes, and the degradation ability of "real" micro-nanoplastics. Then the plastic degradation phenomenon and the accuracy of SERS evaluation method can be fully verified. On this basis, the effects of animal species, dietary characteristics, micro-nanoplastic material type and particle size on the degradation efficiency can be studied. This project will provide convenient analysis methods and tools for the study of marine biodegradation behavior of micro-nanoplastics, explore potential degradable species and strain resources for marine plastic pollution control, and provide new research ideas for revealing the ecological effects and final destination of marine micro-nanoplastics.