Chaisrikhwun Boonphop, Balani Mary Jane Dacillo, Ekgasit Sanong, Xie Yunfei, Ozaki Yukihiro, Pienpinijtham Prompong
Sensor Research Unit (SRU), Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
National Nanotechnology Center of Advanced Structural and Functional Nanomaterials, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
Analyst. 2024 Aug 5;149(16):4158-4167. doi: 10.1039/d4an00702f.
Plastic pollution at the nanoscale continues to pose adverse effects on environmental sustainability and human health. However, the detection of nanoplastics (NPLs) remains challenging due to limitations in methodology and instrumentation. Herein, a "green approach" for surface-enhanced Raman spectroscopy (SERS) was exploited to detect polystyrene nanospheres (PSNSs) in water, employing untreated filter paper and a simple syringe-filtration set-up. This SERS protocol not only enabled the filtration of nano-sized PSNSs, which are smaller than the pore size of the ordinary filter paper, but also offered SERS enhancement by utilizing quasi-spherical-shaped silver nanoparticles (AgNPs) as the SERS-active substrate. The filtering of NPLs was accomplished by adding an aggregating agent to the nanoparticle mixture, which caused the aggregation of NPLs and AgNPs, resulting in a larger cluster and more hot spots for SERS detection. The optimal aggregating agent and its concentration, as well as the volume ratio between the AgNPs and NPLs, were also optimized. This SERS method successfully detected and quantified PSNSs of various sizes (, 100, 300, 460, 600, and 800 nm) down to a limit of detection (LOD) of about 0.31 μg mL. The method was also validated against the presence of several interferents (, salts, sugars, amino acids, and surfactants) and was proven practical, as evidenced by the detection of 800nm PSNSs in drinking and tap water (LODs of 1.47 and 1.55 μg mL, respectively).
纳米级的塑料污染持续对环境可持续性和人类健康造成不利影响。然而，由于方法和仪器的局限性，纳米塑料（NPLs）的检测仍然具有挑战性。在此，利用一种表面增强拉曼光谱（SERS）的“绿色方法”，采用未经处理的滤纸和简单的注射器过滤装置来检测水中的聚苯乙烯纳米球（PSNSs）。这种SERS方案不仅能够过滤尺寸小于普通滤纸孔径的纳米级PSNSs，还通过使用准球形银纳米颗粒（AgNPs）作为SERS活性基底提供SERS增强。通过向纳米颗粒混合物中添加聚集剂来实现NPLs的过滤，这会导致NPLs和AgNPs聚集，形成更大的聚集体和更多用于SERS检测的热点。还优化了最佳聚集剂及其浓度，以及AgNPs与NPLs之间的体积比。这种SERS方法成功地检测并定量了各种尺寸（100、300、460、600和800 nm）的PSNSs，检测限（LOD）约为0.31 μg/mL。该方法还针对几种干扰物（盐、糖、氨基酸和表面活性剂）的存在进行了验证，并被证明是实用的，饮用水和自来水中800nm PSNSs的检测结果（检测限分别为1.47和1.55 μg/mL）证明了这一点。
