This study reported a sandwich SERS structure in detecting SARS-CoV-2 spike protein (SARS-CoV-2 S protein) with high performance. The periodic Ag nanoarrays (AgNAs) functionalized with angiotensin-converting enzyme 2 (ACE2) were utilized as the bottom structure to specifically bound to the SARS-CoV-2 S protein. A complex of SARS-CoV-2 S protein antibody and 4-mercaptobenzoic acid (4-Mba) modified Au nanoparticles (AuNPs@4-Mba@Antibody) were used as nanotags and top SERS enhancing structures. By utilized the “hot spots” in parallel and perpendicular directions, the SERS signals of the 4-Mba as reporters were largely enhanced. By modulated the diameters and the heights of the AgNAs, the SERS performance of the sandwich structures was optimized by using R6G as a stand analyst with limits of detection (LOD) of 1 × 10−9 M. By applied the optimized sandwich structures in detecting SARS-CoV-2 S protein in phosphate buffered saline (PBS) and pharyngeal swabs solution (PSS), the proposed sandwich structure illustrates a high performance, and the LODs were 0.1 fg mL−1 and 1 fg mL−1, respectively. This study presented an efficient way to construct a sandwich SERS structure in directly detecting SARS-CoV-2 S protein and this method illustrates a good potential in viral detection.

中文翻译：

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构建周期性夹心 SERS 结构以高性能检测 SARS-CoV-2 S 蛋白


本研究报道了一种夹心 SERS 结构在检测 SARS-CoV-2 刺突蛋白 （SARS-CoV-2 S 蛋白） 方面表现出色。用血管紧张素转换酶 2 （ACE2） 功能化的周期性 Ag 纳米阵列 （AgNAs） 被用作与 SARS-CoV-2 S 蛋白特异性结合的底部结构。SARS-CoV-2 S 蛋白抗体和 4-巯基苯甲酸 （4-Mba） 修饰的 Au 纳米颗粒 （AuNPs@4-Mba@Antibody） 的复合物被用作纳米标签和顶部 SERS 增强结构。通过利用平行和垂直方向的“热点”，4-Mba 作为记者的 SERS 信号在很大程度上得到了增强。通过调节 AgNAs 的直径和高度，使用 R6G 作为检测限 （LOD） 为 1 × 10−9 M 的林分分析员，优化了夹层结构的 SERS 性能。通过应用优化的夹心结构检测磷酸盐缓冲盐水 （PBS） 和咽拭子溶液 （PSS） 中的 SARS-CoV-2 S 蛋白，所提出的夹心结构表现出高性能，LOD 分别为 0.1 fg mL-1 和 1 fg mL-1。本研究提出了一种构建夹心 SERS 结构直接检测 SARS-CoV-2 S 蛋白的有效方法，该方法在病毒检测中具有良好的潜力。