College of Life Sciences, Anhui Agricultural University, Hefei 230036, P. R. China.
Beijing Institute of Radiation Medicine, Beijing 100850, P. R. China.
Anal Chem. 2020 Dec 1;92(23):15542-15549. doi: 10.1021/acs.analchem.0c03484. Epub 2020 Nov 18.
A rapid and accurate method for detection of virus (SARS-CoV-2)-specific antibodies is important to contain the 2019 coronavirus disease (COVID-19) outbreak, which is still urgently needed. Here, we develop a colorimetric-fluorescent dual-mode lateral flow immunoassay (LFIA) biosensor for rapid, sensitive, and simultaneous detection of SARS-CoV-2-specific IgM and IgG in human serum using spike (S) protein-conjugated SiO@Au@QD nanobeads (NBs) as labels. The assay only needs 1 μL of the serum sample, can be completed within 15 min, and is 100 times more sensitive than the colloidal gold-based LFIA. Two detection modes of our biosensor are available: the colorimetric mode for rapid screening of the patients with suspected SARS-CoV-2 infection without any special instrument and the fluorescent mode for sensitive and quantitative analyses to determine the concentrations of specific IgM/IgG in human serum and detect the infection early and precisely. We validated the proposed method using 16 positive serum samples from patients with COVID-19 and 41 negative samples from patients with other viral respiratory infections. The results demonstrated that combined detection of virus-specific IgM and IgG via SiO@Au@QD LFIA can identify 100% of patients with SARS-CoV-2 infection with 100% specificity.
一种快速、准确检测病毒（SARS-CoV-2）特异性抗体的方法对于控制 2019 年冠状病毒病（COVID-19）的爆发至关重要，这仍然是迫切需要的。在这里，我们开发了一种比色-荧光双模侧向流动免疫分析（LFIA）生物传感器，用于使用与刺突（S）蛋白偶联的 SiO@Au@QD 纳米珠（NBs）作为标记物，快速、灵敏、同时检测人血清中的 SARS-CoV-2 特异性 IgM 和 IgG。该测定仅需要 1μL 的血清样品，可在 15 分钟内完成，比胶体金 LFIA 灵敏 100 倍。我们的生物传感器有两种检测模式：比色模式用于快速筛选疑似 SARS-CoV-2 感染的患者，无需任何特殊仪器；荧光模式用于灵敏和定量分析，以确定人血清中特异性 IgM/IgG 的浓度，并早期、准确地检测感染。我们使用来自 COVID-19 患者的 16 份阳性血清样本和来自其他病毒性呼吸道感染患者的 41 份阴性样本验证了该方法。结果表明，通过 SiO@Au@QD LFIA 联合检测病毒特异性 IgM 和 IgG 可 100%特异性识别 SARS-CoV-2 感染的患者。
