State Key Laboratory of Tea Plant Biology and Utilization, Joint Research Center for Food Nutrition and Health of IHM, Anhui Provincial Key Laboratory of Food Safety Monitoring and Quality Control, School of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, China.
Key Laboratory of Agri-products Quality and Biosafety (Anhui Agricultural University), Ministry of Education, Hefei 230036, China.
J Agric Food Chem. 2024 Nov 6;72(44):24786-24796. doi: 10.1021/acs.jafc.4c02612. Epub 2024 Oct 28.
Sensitive and accurate detection of thiamethoxam in tea is significant to ensuring consumer health. In this study, surface-enhanced Raman scattering (SERS) tags were prepared by using a polyphenol-mediated coating engineering strategy. This approach involved the self-assembly of tannic acid (TA) and self-polymerization of benzene-1,4-dithiol (BDT) on the surface of gold nanoparticles, resulting in the formation of Au@pBDT-TA. The SERS tags possess high Raman signals and antibody adsorption properties, avoiding the complex decoration or label steps of SERS reporters. We discovered that Au@pBDT-TA, composed of gold nanoparticles at 40 nm and a pBDT-TA thickness of 10 nm, was optimal for the development of the SERS lateral flow immunoassay (LFIA). In comparison to the gold nanoparticle-based LFIA, the SERS-LFIA demonstrated 4-fold and 720-fold enhancements in visual and quantitative limits of detection in buffer solution. The SERS-LFIA demonstrated quantitative limits of detection of 0.06 and 0.1 ng/g for black and green tea, respectively, with a broader linear range spanning over 2 orders of magnitude and a short detection time of 20 min. The proposed SERS-LFIA not only offers a sensitive and reliable method for monitoring thiamethoxam in tea but also possesses a versatile potential that can be easily adapted for the trace detection of various other targets.
灵敏、准确地检测茶叶中的噻虫嗪对保障消费者健康具有重要意义。本研究采用多酚介导的涂层工程策略制备表面增强拉曼散射（SERS）标记物。该方法涉及单宁酸（TA）的自组装和苯-1,4-二硫醇（BDT）的自聚合在金纳米粒子表面，形成 Au@pBDT-TA。SERS 标记物具有高拉曼信号和抗体吸附性能，避免了 SERS 报告物的复杂修饰或标记步骤。我们发现，由 40nm 金纳米粒子和 10nm pBDT-TA 组成的 Au@pBDT-TA 最适合开发 SERS 侧向流免疫分析（LFIA）。与基于金纳米粒子的 LFIA 相比，SERS-LFIA 在缓冲溶液中的视觉和定量检测限分别提高了 4 倍和 720 倍。SERS-LFIA 对黑茶和绿茶的定量检测限分别为 0.06 和 0.1ng/g，线性范围跨越 2 个数量级，检测时间短至 20min。所提出的 SERS-LFIA 不仅为监测茶叶中的噻虫嗪提供了一种灵敏、可靠的方法，而且具有广泛的潜力，可轻松适应各种其他目标的痕量检测。
