Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China; Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China.
Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China; Research Institute for Future Food, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China; State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong SAR, China.
J Environ Sci (China). 2022 Nov;121:58-64. doi: 10.1016/j.jes.2021.08.044. Epub 2022 Feb 1.
Microplastics represent an emerging environmental problem worldwide, raising ecological and food safety concerns. Compared to microplastics, there is growing evidence of an even higher abundance of submicro- and nanoplastics in the environment, but a reliable monitoring method for detecting these smaller-sized plastics is lacking. Herein we presented the application of surface-enhanced Raman scattering (SERS) for this purpose. Particles of polystyrene (PS; 600 nm) were used as the probe analyte. Gold nanourchins (AuNU; 50 nm), i.e. urchin-shaped nanoparticles with irregular spikes around the core, were used as the SERS-active substrate. The effectiveness of SERS on PS was evaluated at a single-particle level with different numbers of AuNU in order to determine the minimum conditions required for the onset of the SERS effect. Our findings suggest that SERS of a single particle of PS can be induced by as few as 1-5 particles of AuNU, and that the use of excitation wavelength at 785 nm is appropriate to meet the red-shifted surface plasmon resonance of AuNU upon aggregation. These specifications provide additional information for the development of SERS-based tools for detecting plastic particles < 1 µm in food and environmental samples.
微塑料是一种全球性的新兴环境问题，引发了人们对生态和食品安全的担忧。相比之下，越来越多的证据表明，环境中存在更高丰度的亚微米和纳米塑料，但缺乏可靠的监测方法来检测这些更小尺寸的塑料。在此，我们介绍了表面增强拉曼散射（SERS）在这方面的应用。聚苯乙烯（PS；600nm）颗粒被用作探针分析物。金纳米刺（AuNU；50nm），即具有核心周围不规则刺的刺状纳米粒子，被用作 SERS 活性衬底。通过使用不同数量的 AuNU 在单粒子水平上评估 SERS 对 PS 的有效性，以确定 SERS 效应起始所需的最小条件。我们的研究结果表明，单个 PS 颗粒的 SERS 可以通过 1-5 个 AuNU 颗粒诱导，并且使用 785nm 的激发波长适合满足 AuNU 聚集时的表面等离子体共振红移。这些规格为开发基于 SERS 的工具提供了更多信息，用于检测食品和环境样品中 <1μm 的塑料颗粒。
