Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
Upper Midwest Water Science Center, U.S. Geological Survey, Madison, Wisconsin 53726, United States.
Environ Sci Technol. 2024 Nov 12;58(45):20172-20180. doi: 10.1021/acs.est.4c06503. Epub 2024 Oct 29.
In freshwater environments, low-micrometer microplastics (LMMPs) have captured significant attention due to their prevalence and toxicity. Yet, rapid detection of LMMPs (1-10 μm) at the single-particle level within complex freshwater matrices remains a hurdle. We developed an adaptable plasmonic membrane sensor for fast detection of individual LMMPs in eutrophic lake waters. The plasmonic membrane sensor functions both as a membrane filter and as a sensor for LMMP collection and analysis. Among the four types of membrane sensors, polycarbonate track-etch (PCTE) membrane sensors exhibit superior imaging quality for LMMPs due to their flat and homogeneous surfaces. Besides the significantly improved imaging contrast and reduced background interferences, the Raman intensity of LMMPs is enhanced by 48% ± 25% on PCTE membrane sensors compared to unmodified membranes. The increased Raman intensities of a chemical probe with an increasing gold layer thickness and a decreasing membrane pore size suggest a surface-enhanced Raman scattering effect from the membrane sensors. The membrane sensors achieve a detection limit of 1 μg/L and an ultrafast scanning time of 0.01 s for individual LMMPs across natural eutrophic lake water. The developed membrane sensors offer an adaptable tool for the swift and reliable detection of individual LMMPs in complex environmental matrices.
在淡水环境中，由于其普遍性和毒性，低微米级微塑料（LMMP）引起了人们的极大关注。然而，在复杂的淡水基质中，快速检测单个 LMMP（1-10μm）仍然是一个难题。我们开发了一种适应性强的等离子体膜传感器，用于快速检测富营养化湖水中的单个 LMMP。该等离子体膜传感器既是膜过滤器，也是用于 LMMP 收集和分析的传感器。在四种类型的膜传感器中，聚碳酸酯轨迹蚀刻（PCTE）膜传感器由于其平坦和均匀的表面，对 LMMP 具有优异的成像质量。与未修饰的膜相比，PCTE 膜传感器上 LMMP 的成像对比度显著提高，背景干扰减少，拉曼强度增强了 48%±25%。随着金层厚度的增加和膜孔尺寸的减小，化学探针的拉曼强度增加，表明膜传感器具有表面增强拉曼散射效应。该膜传感器在天然富营养化湖水的单个 LMMP 检测中，检测限达到 1μg/L，超快扫描时间为 0.01s。所开发的膜传感器为在复杂环境基质中快速可靠地检测单个 LMMP 提供了一种适应性强的工具。
