Abstract：
A lateral flow assay (LFA) strip based on dual 5,5\'-dithiobis-(2-nitrobenzoic acid) (DTNB)-encoded satellite Fe3O4@Au (Mag@Au) SERS tags with nanogap is reported for ultrasensitive and simultaneous diagnosis of two SARS-CoV-2 functional proteins. Composed of Fe3O4 core, satellite gold shell with nanogaps, and double-layer DTNB, the Mag@Au nanoparticles with an average size of 238 nm were designed as multifunctional tags to efficiently enrich the target SARS-CoV-2 protein from complex samples, significantly enhancing the SERS signal of the LFA strip and provide quantitative SERS detection of analyte on test lines. The developed dual DTNB-encoded satellite Mag@Au-based LFA allowed simultaneous quantification of spike (S) protein and nucleocapsid (NP) protein with detection limits of 23 pg mL-1 and 2 pg mL-1, respectively, lower than commercial ELISA kits and reported SERS-LFA detection system-based Au NPs and Fe3O4@3 nm Au MNPs. This magnetic SERS-LFA also showed high performance of multi-variant strain detection and further distinguished clinical samples of Omicron variant infection, demonstrating the potential of in situ detection of respiratory virus diseases.
摘要：
据报道，基于双5,5'-二硫代双-（2-硝基苯甲酸）（DTNB）编码的卫星Fe3O4@Au（Mag@Au）SERS标签的侧流测定（LFA）条带具有纳米间隙，可用于超灵敏和同时诊断两种SARS-CoV-2功能蛋白。由Fe3O4芯组成，带有纳米间隙的卫星金壳，和双层DTNB，平均尺寸为238nm的Mag@Au纳米颗粒被设计为多功能标签，以有效地从复杂样品中富集目标SARS-CoV-2蛋白，显著增强LFA条的SERS信号并提供测试线上分析物的定量SERS检测。开发的双DTNB编码的基于Mag@Au的卫星LFA允许同时定量峰（S）蛋白和核衣壳（NP）蛋白，检测限分别为23pgmL-1和2pgmL-1，低于商业ELISA试剂盒，并报道了基于SERS-LFA检测系统的AuNP和Fe3O4@3nmAuMNPs。这种磁性SERS-LFA还显示出多变异株检测的高性能，并进一步区分了Omicron变异感染的临床样品，证明了原位检测呼吸道病毒疾病的潜力。
