Rapid vertical flow immunoassay on AuNP plasmonic paper for SERS-based point of need diagnostics
Rapid vertical flow immunoassay on AuNP plasmonic paper for SERS-based point of need diagnostics
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DOI：
10.1016/j.talanta.2020.121739
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发表时间：
2021-02-01
期刊：
影响因子：
6.1
通讯作者：
Driskell, Jeremy D.
中科院分区：
文献类型：
--
作者：
Frimpong, Richard;Jang, Wongi;Driskell, Jeremy D.
基于 SERS 的即时诊断免疫分析是一种有前景的工具，可促进早期疾病诊断和疾病控制的生物标志物检测。该技术基于夹层系统，其中抗原首先被选择性等离子体纸基质捕获，然后用外在拉曼标签 (ERL) 进行标记，该标签由 60 nm 金纳米颗粒 (AuNP) 组成，混合单层检测抗体和 4-硝基苯硫醇 (NBT) 作为拉曼报告分子。在这里，我们报告了使用 AuNP 改性滤纸作为垂直流格式的新型捕获膜。这种垂直流动配置提供了样品和标记通过捕获基质的可重复流动，以克服扩散限制动力学并显着缩短测定时间。选择滤纸是因为其经济性和可用性，而嵌入的 AuNPs 最大限度地提高了等离激元耦合与 ERL 和 SERS 增强功能。此外，嵌入的 AuNP 作为支架来固定捕获抗体以特异性结合抗原。在这项工作中，开发了一种用于检测小鼠 IgG 的基于 SERS 的快速垂直流 (SERS-RVF) 免疫测定法，以建立原理验证。检测条件的优化使检测限达到 3 ng/mL，与多孔板中进行的更传统的格式相当，并且检测时间显着缩短至不到 2 分钟。此外，对正常小鼠血清中的 IgG 进行了准确定量，以验证 SERS-RVF 测定在生物样品分析中的应用。这些结果凸显了 SERSRVF 平台在需求点测试方面的潜在优势。
SERS based immunoassays for point-of-care diagnostics are a promising tool to facilitate biomarker detection for early disease diagnosis and disease control. The technique is based on a sandwiched system in which antigen is first captured by a selective plasmonic paper substrate and then labeled by an extrinsic Raman label (ERL), consisting of a 60 nm gold nanoparticle (AuNP) functionalized with a mixed monolayer of detection antibody and 4-nitrobenezenethiol (NBT) as a Raman reporter molecule. Here, we report on the use of AuNP modified filter paper as a novel capture membrane in a vertical flow format. This vertical flow configuration affords reproducible flow of sample and label through the capture substrate to overcome diffusion limited kinetics and significantly reduced assay time. The filter paper was selected due to its affordability and availability, while the embedded AuNPs maximized plasmonic coupling with the ERLs and SERS enhancement. Additionally, the embedded AuNP served as a scaffold to immobilize capture antibody to specifically bind antigen. In this work, a SERS-based rapid vertical flow (SERS-RVF) immunoassay for detection of mouse IgG was developed to establish proof-of-principle. Optimization of assay conditions led to a limit of detection of 3 ng/mL, which is comparable to more traditional formats carried out in multi-well plates, and significantly reduced assay time to less than 2 min. Additionally, IgG was accurately quantified in normal mouse serum to validate the SERS-RVF assay for application to the analysis of biological samples. These results highlight the potential advantages of the SERSRVF platform for point-of-need testing.