NanoTechnas-Center of Nanotechnology and Materials Science, Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko Str. 24, LT-03225 Vilnius, Lithuania.
Int J Mol Sci. 2024 Aug 6;25(16):8574. doi: 10.3390/ijms25168574.
The strong immunogenicity of the SARS-CoV-2 nucleocapsid protein is widely recognized, and the detection of specific antibodies is critical for COVID-19 diagnostics in patients. This research proposed direct, label-free, and sensitive detection of antibodies against the SARS-CoV-2 nucleocapsid protein (anti-SCoV2-rN). Recombinant SARS-CoV-2 nucleocapsid protein (SCoV2-rN) was immobilized by carbodiimide chemistry on an SPR sensor chip coated with a self-assembled monolayer of 11-mercaptoundecanoic acid. When immobilized under optimal conditions, a SCoV2-rN surface mass concentration of 3.61 ± 0.52 ng/mm was achieved, maximizing the effectiveness of the immunosensor for the anti-SCoV2-rN determination. The calculated value of 6.49 × 10 ± 5.3 × 10 M confirmed the good affinity of the used monoclonal anti-SCoV2-rN antibodies. The linear range of the developed immunosensor was from 0.5 to 50 nM of anti-SCoV2-rN, where the limit of detection and the limit of quantification values were 0.057 and 0.19 nM, respectively. The immunosensor exhibited good reproducibility and specificity. In addition, the developed immunosensor is suitable for multiple anti-SCoV2-rN antibody detections.
SARS-CoV-2 核衣壳蛋白具有很强的免疫原性，这一点已得到广泛认可，针对 SARS-CoV-2 核衣壳蛋白的特异性抗体检测对于 COVID-19 患者的诊断至关重要。本研究提出了一种针对 SARS-CoV-2 核衣壳蛋白（anti-SCoV2-rN）的直接、无标记、灵敏的抗体检测方法。通过碳二亚胺化学将 SARS-CoV-2 核衣壳蛋白（SCoV2-rN）固定在涂有 11-巯基十一烷酸自组装单层的 SPR 传感器芯片上。在最佳条件下固定时，可获得 3.61 ± 0.52 ng/mm 的 SCoV2-rN 表面质量浓度，从而使该免疫传感器对 anti-SCoV2-rN 的测定效果最大化。计算得出的 6.49 × 10 ± 5.3 × 10 M 值证实了所使用的单克隆抗-SCoV2-rN 抗体具有良好的亲和力。所开发的免疫传感器的线性范围为 0.5 至 50 nM 的 anti-SCoV2-rN，检测限和定量限分别为 0.057 和 0.19 nM。该免疫传感器具有良好的重现性和特异性。此外，所开发的免疫传感器适用于多种 anti-SCoV2-rN 抗体的检测。
