Shen Haicong, Song Eunyeong, Wang Yang, Meng Lingyan, Dong Jing, Lin Bingqian, Huang Di, Guan Zhichao, Yang Chaoyong, Zhu Zhi
Key Laboratory for Chemical Biology of Fujian Province, MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, China.
Anal Bioanal Chem. 2022 Jan;414(1):507-513. doi: 10.1007/s00216-021-03419-z. Epub 2021 Jun 5.
As a paper-based analytical platform, lateral flow assay (LFA) gets benefit from the rapid analysis, low cost, high selectivity, good stability, and user-friendliness, and thus has been widely used in rapid screening or assisted diagnosis. Nevertheless, LFA still suffers from low detection sensitivity via the naked eye, limiting its applications to qualitative and semi-quantitative tests. To enhance the signal readout, various nanoparticle signal tags have been employed to replace traditional colloidal gold nanoparticles (AuNPs), such as fluorescent nanoparticles (FNPs), magnetic nanoparticles (MNPs), and Raman reporter-labeled nanoparticles. In particular, Raman reporter-labeled nanoparticles are extremely sensitive due to remarkable signal enhancement effect on metal surface. However, the application of LFA is still hampered by the poor stability of Raman reporter-labeled nanoparticles. Herein, we developed an in situ Raman enhancement strategy to create a surface-enhanced Raman scattering (SERS) signal on the AuNPs, shortened as "i-SERS," which not only preserves the original advantages of the colloidal gold strip (AuNPs-LFA), but also realizes highly sensitive and quantitative detection. We applied the i-SERS for procalcitonin (PCT) detection. The experimental process takes only 16 min, and the limit of detection (LOD) is 0.03 ng mL, far below the value using AuNPs-LFA. These results indicate that i-SERS assay was highly sensitive and suitable for the rapid detection of PCT.
作为一种基于纸质的分析平台，侧向流动分析（LFA）受益于快速分析、低成本、高选择性、良好稳定性和用户友好性，因此已广泛应用于快速筛查或辅助诊断。然而，LFA通过肉眼检测的灵敏度仍然较低，限制了其在定性和半定量测试中的应用。为了增强信号读出，已采用各种纳米颗粒信号标签来取代传统的胶体金纳米颗粒（AuNP），如荧光纳米颗粒（FNP）、磁性纳米颗粒（MNP）和拉曼报告分子标记的纳米颗粒。特别是，拉曼报告分子标记的纳米颗粒由于对金属表面具有显著的信号增强作用而极其灵敏。然而，LFA的应用仍然受到拉曼报告分子标记的纳米颗粒稳定性差的阻碍。在此，我们开发了一种原位拉曼增强策略，以在AuNP上产生表面增强拉曼散射（SERS）信号，简称为“i-SERS”，它不仅保留了胶体金试纸条（AuNPs-LFA）的原有优势，还实现了高灵敏度和定量检测。我们将i-SERS应用于降钙素原（PCT）检测。实验过程仅需16分钟，检测限（LOD）为0.03 ng/mL，远低于使用AuNPs-LFA的值。这些结果表明，i-SERS分析具有高灵敏度，适用于PCT的快速检测。
