State Key Laboratory of Chemical Safety, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China.
College of Chemistry and Environment, Fujian Provincial Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000, China.
Anal Methods. 2024 Apr 25;16(16):2597-2605. doi: 10.1039/d4ay00347k.
The highly infectious characteristics of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), highlight the necessity of sensitive and rapid nucleocapsid (N) protein-based antigen testing for early triage and epidemic management. In this study, a colorimetric and photothermal dual-mode lateral flow immunoassay (LFIA) platform for the rapid and sensitive detection of the SARS-CoV-2 N protein was developed based on gold nanorods (GNRs), which possessed tunable local surface plasma resonance (LSPR) absorption peaks from UV-visible to near-infrared (NIR). The LSPR peak was adjusted to match the NIR emission laser 808 nm by controlling the length-to-diameter ratio, which could maximize the photothermal conversion efficiency and achieve photothermal detection signal amplification. Qualitative detection of SARS-CoV-2 N protein was achieved by observing the strip color, and the limit of detection was 2 ng mL, while that for photothermal detection was 0.096 ng mL. Artificial saliva samples spiked with the N protein were analyzed with the recoveries ranging from 84.38% to 107.72%. The intra-assay and inter-assay coefficients of variation were 6.76% and 10.39%, respectively. We further evaluated the reliability of this platform by detecting 40 clinical samples collected from nasal swabs, and the results matched well with that of nucleic acid detection (87.5%). This method shows great promise in early disease diagnosis and screening.
新型冠状病毒病（COVID-19）是由严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）引起的，具有高度传染性，这凸显了基于核衣壳（N）蛋白的敏感、快速抗原检测在早期分诊和疫情管理中的必要性。本研究基于金纳米棒（GNRs），开发了一种用于快速灵敏检测 SARS-CoV-2 N 蛋白的比色和光热双模式侧向流动免疫分析（LFIA）平台，GNRs 具有从紫外可见到近红外（NIR）可调谐的局域表面等离子体共振（LSPR）吸收峰。通过控制长度与直径比来调整 LSPR 峰以匹配 NIR 发射激光 808nm，从而可以最大化光热转换效率并实现光热检测信号放大。通过观察条带颜色实现对 SARS-CoV-2 N 蛋白的定性检测，检测限为 2ng mL，而光热检测的检测限为 0.096ng mL。用含 N 蛋白的人工唾液样本进行分析，回收率在 84.38%至 107.72%之间。内和间分析的变异系数分别为 6.76%和 10.39%。我们通过检测从鼻拭子中收集的 40 个临床样本进一步评估了该平台的可靠性，结果与核酸检测（87.5%）吻合良好。该方法在早期疾病诊断和筛查中具有很大的应用前景。
