Chi Huanyu, Wang Congcheng, Wang Zhien, Zhu Hongni, Mesias Vince St Dollente, Dai Xin, Chen Qing, Liu Wei, Huang Jinqing
HKUST-Shenzhen Research Institute, No. 9 Yuexing first RD, Hi-tech Park, Nanshan, Shenzhen 518057, China.
Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
Analyst. 2020 Aug 7;145(15):5158-5165. doi: 10.1039/d0an00999g. Epub 2020 Jul 7.
Surface-enhanced Raman spectroscopy (SERS) enables pesticide detection at the point-of-need, but its practical application is limited by expensive and disposable SERS substrates. Here, we report a reusable nanoporous silver (NPAg) sheet for the SERS detection of organochlorine pesticides, aiming to maximize the cost-efficiency of substrate regeneration. The NPAg sheet is prepared by a reduction-induced decomposition method without chemical induced random aggregations. This SERS substrate is sensitive to various analytes regardless of their affinity to a metal surface such as rhodamine B, dichlorodiphenyl-trichloroethane (DDT), and lindane due to its large surface area and the coral rock-like morphology. The SERS signal of lindane, a typical organochlorine pesticide, is identified and quantified with a minimum detectable concentration of 3 × 10 M (87 ppb), which is below the maximum residue limits in various foods set by the regulators across the world. More importantly, after a few minutes of ultrasonic cleaning in water, the NPAg sheet can be reused at least 20 times with a reproducible SERS activity. Furthermore, the NPAg sheet remains stable in terms of its sensitivity and reusability after several months of bare strorage. Therefore, the NPAg sheet as a SERS substrate holds great promise for mass production and convenient applications in low-cost pesticide analysis.
表面增强拉曼光谱（SERS）能够在需要时进行农药检测，但其实际应用受到昂贵且一次性使用的SERS基底的限制。在此，我们报道了一种用于SERS检测有机氯农药的可重复使用的纳米多孔银（NPAg）片，旨在最大限度地提高基底再生的成本效益。NPAg片通过还原诱导分解法制备，无化学诱导的随机聚集。这种SERS基底由于其大表面积和珊瑚岩状形态，对各种分析物敏感，无论它们对金属表面的亲和力如何，如罗丹明B、二氯二苯三氯乙烷（DDT）和林丹。典型有机氯农药林丹的SERS信号被识别并定量，最低检测浓度为3×10⁻⁸ M（87 ppb），低于世界各国监管机构设定的各种食品中的最大残留限量。更重要的是，在水中超声清洗几分钟后，NPAg片可重复使用至少20次，且具有可重复的SERS活性。此外，在裸存几个月后，NPAg片在灵敏度和可重复使用性方面保持稳定。因此，NPAg片作为SERS基底在低成本农药分析的大规模生产和便捷应用方面具有巨大潜力。
