表面增强拉曼散射探针标记纳米塑料在菲律宾蛤仔（Ruditapes philippinarum）体内行为研究

	表面增强拉曼散射探针标记纳米塑料在菲律宾蛤仔（Ruditapes philippinarum）体内行为研究
	杜泓钰
学位类型	硕士
导师	王运庆
	2022-05-13
培养单位	中国科学院烟台海岸带研究所
学位授予单位	中国科学院大学
学位授予地点	中国科学院烟台海岸带研究所
学位名称	硕士
学位专业	海洋化学
关键词	表面增强拉曼散射纳米塑料聚苯乙烯菲律宾蛤仔原位检测 Surface enhanced Raman scattering Nanoplastics Polystyrene Ruditapes philippinarum In vivo distribution
摘要	近年来，微纳塑料作为新兴的海洋污染物问题越来越受到公众和科学家的关注。海洋中大块塑料在紫外线照射、高温、机械摩擦等作用下逐渐被分解成碎片，其中直径小于5 mm的颗粒被定义为微塑料，小于1 µm的颗粒被定义为纳米塑料。微纳塑料长期而广泛地赋存在水体和沉积物等环境介质，可以被浮游、底栖等多种海洋动物摄取，引发毒性效应，并可能沿着食物链传递，给人类健康造成了威胁。深入掲示微纳塑料和海洋生物的相互作用规律，对于深入理解其环境生态效应、厘清在海洋环境中的归趋具有重要意义。光学成像示踪是纳米塑料体内行为研究的关键技术。传统荧光标记粒子和成像方法存在生物背景干扰、无法准确定量、易造成假阳性结果等瓶颈问题。本论文研发了以金纳米粒子为核心，以聚苯乙烯（PS）为壳层的表面增强拉曼散射（SERS）标记纳米塑料模型颗粒，具有高灵敏度、高抗干扰能力和高稳定性等优势。同时，进一步选择具有重要的生态环境意义、与人类饮食联系密切的滤食性双壳贝类菲律宾蛤仔（Ruditapes philippinarum）为模式生物，研究了单分散（100 nm）和聚集状态（1.5 µm）的纳米塑料模型颗粒在其体内的分布、蓄积和代谢行为。利用特征SERS信号和拉曼成像技术，可以快速准确地获得纳米塑料的体内分布情况；通过电感耦合等离子体质谱（ICP-MS）测定金元素含量，可以对纳米塑料的含量进行定量分析。结果显示，纳米塑料可以被菲律宾蛤仔吸收并转运至鳃、输水管、斧足、闭壳肌、外套膜和消化腺等主要器官。其中，消化腺是纳米塑料的主要蓄积器官，含量占全身的86.7%。经过11天净化代谢后，体内90 %纳米塑料可被排出体外。聚集状态的纳米塑料表现出与单分散纳米塑料相似的分布和代谢趋势，但是各个器官中的蓄积含量降低了15.2%-77.6%。同时，研究发现表面吸附也是导致纳米塑料在生物体内积累的重要途径。此外，煮沸等烹饪处理不会减少所食用的生物体内纳米塑料的含量。本研究为纳米塑料在海洋生物体内分布、蓄积和代谢提供了新的定量分析方法，为近海污染背景下菲律宾蛤仔养殖安全和食品安全评估提供了基础数据。揭示纳米塑料经海洋动物消化产生后界面的理化性质变化，是理解其环境命运的重要一环，但目前尚缺少高效便捷的分析工具和筛选评估方法。本研究发展了新型“磁性SERS@PS”多功能塑料模型粒子，应用于探索评估菲律宾蛤仔体内纳米塑料的界面性质变化研究。探针结构由四部分组成，自内向外分别为四氧化三铁（Fe3O4）磁性粒子核心、金纳米粒子、pH响应拉曼报告分子4-巯基吡啶（4-Mpy）、PS纳米壳层。通过磁分离技术回收粪便中消化后的粒子，借助SERS光谱采集和成像技术分析粒子SERS信号对pH变化的响应，指征PS壳层渗透性变化。结果表明，模型颗粒经菲律宾蛤仔消化后，4-Mpy的pH敏感峰强度变化，拉曼峰1005 cm-1/1094 cm-1比例上升，表明塑料模型颗粒的PS壳层渗透性提高，使H+通过孔隙扩散到纳米模型颗粒内部，暗示PS壳层发生溶胀或降解。该结果与具有塑料降解能力的黄粉虫体内结果相一致。“磁性SERS@PS”模型粒子有望成为揭示纳米塑料的海洋生物体内性质变化、快速筛查潜在塑料降解物种的新方法和新工具。
其他摘要	In recent years, micro-nano plastics have attracted more and more attention from the public and scientists as an emerging marine pollutant. Large pieces of plastic in the ocean are gradually decomposed into fragments under the action of ultraviolet radiation, high temperature, mechanical friction, etc., among which particles smaller than 5 mm in diameter are defined as microplastics, and particles smaller than 1 µm are defined as nanoplastics. Micro-nanoplastics have long-term and extensive existence in environmental media such as water bodies and sediments, and can be ingested by plankton, benthic and other marine animals, causing toxic effects, and may be transmitted along the food chain, posing a threat to human health. It is of great significance to deeply understand the interaction law of micro-nano plastics and marine organisms for in-depth understanding of their environmental ecological effects and clarify their fate in the marine environment.Optical imaging tracing is a key technology for the study of nanoplastics in vivo behavior. Traditional fluorescently labeled particles and imaging methods have bottlenecks such as biological background interference, inability to accurately quantify, and easy to cause false positive results. In this study, surface-enhanced Raman scattering (SERS)-labeled nanoplastic model particles with gold nanoparticles as the core and polystyrene (PS) as the shell were developed, which have high sensitivity, high anti-interference ability and high stability and other advantages. We further selected Ruditapes philippinarum, a filter-feeding bivalve mollusk that has important ecological significance and is closely related to human diet, as a model organism, and studied plastic models in monodisperse (100 nm) and aggregated states (1.5 µm). Distribution, accumulation, and metabolic behavior of particles in their body. Using characteristic SERS signal and Raman imaging technology, the in vivo distribution of micro-nano plastics can be quickly and accurately obtained; the content of micro-nano plastics can be quantitatively analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to determine the content of gold elements. The results showed that nanoplastics could be absorbed by Philippine clam and transported to major organs such as gills, aqueducts, axopods, adductor muscles, mantle, and digestive glands. Among them, digestive glands are the main accumulation organs of micro-nano plastics, accounting for 86.7% of the whole body. After 11 days of purification and metabolism, 90% of the nanoplastics in the body can be excreted. The aggregated nanoplastics showed similar distribution and metabolic trends as monodisperse nanoplastics, however the accumulated content in each organ decreased by 15.2%-77.6%. At the same time, it was found that surface adsorption is also an important way to lead to the accumulation of nanoplastics in vivo. In addition, cooking treatments such as boiling do not reduce the amount of nanoplastics in the edible body. This study provides a new quantitative analysis method for the distribution, accumulation, and metabolism of nanoplastics in marine organisms, and provides basic data for the safety and food safety assessment of Philippine clam aquaculture under the background of offshore pollution.Revealing the physical and chemical properties of the interface of micro-nano plastics after being digested by marine animals is an important part of understanding their environmental fate. However, efficient, and convenient analysis tools and screening evaluation methods are still lacking. In this study, a novel "magnetic SERS@PS" multifunctional plastic model particle was developed to explore and evaluate the interfacial properties of nanoplastics in Ruditapes philippinarum. The probe structure is composed of four parts, from the inside to the outside, they are the core of iron tetroxide (Fe3O4) magnetic particle, gold nanoparticles, pH-responsive Raman reporter molecule 4-mercaptopyridine (4-Mpy), and PS nanoshell. The digested particles in the feces were recovered by magnetic separation technology, and the response of the particle SERS signal to pH changes was analyzed by means of SERS spectrum acquisition and imaging technology, indicating changes in PS shell permeability. The results showed that the pH-sensitive peak intensity of 4-Mpy changed and the ratio of the Raman peak at 1005 cm-1/1094 cm-1 risen after the model particles were digested by Ruditapes philippinarum, indicating that the PS shell permeability of the plastic model particles increased, making the plastic model particles more permeable. H+ diffused into the model nanoparticles through the pores, suggesting that the PS shell was swollen or degraded. This result is consistent with the in vivo results of Tenebrio molitor with plastic-degrading ability. The "magnetic SERS@PS" model particle is expected to be a new method and a new tool to reveal the changes in the properties of nanoplastics in marine organisms, and to rapidly screen potential plastic-degrading species.
页数	63
语种	中文
文献类型	学位论文
条目标识符	http://ir.yic.ac.cn/handle/133337/34403
专题	中国科学院烟台海岸带研究所知识产出_学位论文中国科学院烟台海岸带研究所知识产出
推荐引用方式 GB/T 7714	杜泓钰. 表面增强拉曼散射探针标记纳米塑料在菲律宾蛤仔（Ruditapes philippinarum）体内行为研究[D]. 中国科学院烟台海岸带研究所. 中国科学院大学,2022.

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