Department of Biomedical Engineering, Erciyes University, Kayseri 38039, Turkey.
NanoThera Lab, ERFARMA-Drug Application and Research Center, Erciyes University, 38039, Kayseri, Turkey.
Analyst. 2022 Mar 14;147(6):1213-1221. doi: 10.1039/d1an01989a.
COVID-19 has caused millions of cases and deaths all over the world since late 2019. Rapid detection of the virus is crucial for controlling its spread through a population. COVID-19 is currently detected by nucleic acid-based tests and serological tests. However, these methods have limitations such as the requirement of high-cost reagents, false negative results and being time consuming. Surface-enhanced Raman scattering (SERS), which is a powerful technique that enhances the Raman signals of molecules using plasmonic nanostructures, can overcome these disadvantages. In this study, we developed a virus-infected cell model and analyzed this model by SERS combined with Principal Component Analysis (PCA). HEK293 cells were transfected with plasmids encoding the nucleocapsid (N), membrane (M) and envelope (E) proteins of SARS-CoV-2 polyethyleneimine (PEI). Non-plasmid transfected HEK293 cells were used as the control group. Cellular uptake was optimized with green fluorescence protein (GFP) plasmids and evaluated by fluorescence microscopy and flow cytometry. The transfection efficiency was found to be around 60%. The expression of M, N, and E proteins was demonstrated by western blotting. The SERS spectra of the total proteins of transfected cells were obtained using a gold nanoparticle-based SERS substrate. Proteins of the transfected cells have peak positions at 646, 680, 713, 768, 780, 953, 1014, 1046, 1213, 1243, 1424, 2102, and 2124 cm. To reveal spectral differences between plasmid transfected cells and non-transfected control cells, PCA was applied to the spectra. The results demonstrated that SERS coupled with PCA might be a favorable and reliable way to develop a rapid, low-cost, and promising technique for the detection of COVID-19.
自 2019 年底以来，COVID-19 在全球范围内已导致数百万人感染和死亡。快速检测病毒对于通过人群控制其传播至关重要。COVID-19 目前通过核酸检测和血清学检测来检测。然而，这些方法存在一些局限性，例如需要高成本的试剂、假阴性结果和耗时等。表面增强拉曼散射（SERS）是一种强大的技术，它使用等离子体纳米结构增强分子的拉曼信号，可以克服这些缺点。在本研究中，我们建立了一种病毒感染的细胞模型，并通过 SERS 结合主成分分析（PCA）对该模型进行了分析。HEK293 细胞用编码 SARS-CoV-2 核衣壳（N）、膜（M）和包膜（E）蛋白的质粒转染。非质粒转染的 HEK293 细胞作为对照组。通过绿色荧光蛋白（GFP）质粒优化细胞摄取，并通过荧光显微镜和流式细胞术进行评估。转染效率约为 60%。通过 Western blot 证明了 M、N 和 E 蛋白的表达。使用基于金纳米颗粒的 SERS 基底获得转染细胞总蛋白的 SERS 光谱。转染细胞的蛋白质在 646、680、713、768、780、953、1014、1046、1213、1243、1424、2102 和 2124 cm 处有峰位。为了揭示转染细胞和非转染对照细胞之间的光谱差异，我们对光谱进行了 PCA 分析。结果表明，SERS 与 PCA 相结合可能是一种快速、低成本、有前途的 COVID-19 检测技术的有利可靠方法。
