Sathishkumar N, Camacho Valenzuela Jose Gilberto, Le Nguyen H, Yong Anthony K C, Rossotti Martin A, Dahmer Joshua, Sklavounos Alexandros A, Plante Martin, Brassard Daniel, Malic Lidija, Moraitis Anna N, Biga Ruzica, El Idrissi Imane, Tanha Jamshid, Labrecque Jean, Veres Teodor, Wheeler Aaron R
Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3H6, Canada.
Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, Ontario, M5S 3E1, Canada.
Lab Chip. 2025 Jun 24;25(13):3197-3207. doi: 10.1039/d5lc00308c.
Population assessments of infection and immunity status are critical for public health response to infectious disease. Most microfluidic tools are developed to assess one or the other - few assess both. This study introduces a multiplexed, fully automated digital microfluidic (DMF) platform designed to detect viral protein as a proxy for infection status and host IgG and IgA antibodies as a marker for immunity status. SARS-CoV-2 and patient saliva were used as a model system to evaluate the concept. Specifically, the infection assay relied on nanobody-based capture and detection agents specific to SARS-CoV-2 trimeric spike protein, with a limit of detection (LOD) of 3.8 ng mL in saliva. And the immunity relied on monoclonal antibodies for host IgG and IgA specific to SARS-CoV-2 spike S1 domain, with LODs of 4.8 ng mL and 13.3 ng mL in saliva, respectively. Clinical validation in saliva samples from human subjects experiencing symptoms ( = 14) showed strong correlation with PCR and commercial ELISA, achieving 100% sensitivity and 100% specificity for infection detection and 100% sensitivity with 91.7% and 90.9% specificity for host IgG and IgA, respectively. These results highlight potential applications for the new system as a portable diagnostic tool for outbreak surveillance and public health management, as a step toward preparing for the next global pandemic.
对感染和免疫状态进行人群评估对于应对传染病的公共卫生措施至关重要。大多数微流控工具是为评估其中一项而开发的，很少有工具能同时评估两者。本研究引入了一种多路复用、全自动数字微流控（DMF）平台，旨在检测病毒蛋白以代表感染状态，检测宿主IgG和IgA抗体以作为免疫状态的标志物。以严重急性呼吸综合征冠状病毒2（SARS-CoV-2）和患者唾液作为模型系统来评估这一概念。具体而言，感染检测方法依赖于针对SARS-CoV-2三聚体刺突蛋白的基于纳米抗体的捕获和检测试剂，唾液中的检测限（LOD）为3.8 ng/mL。免疫检测则依赖于针对SARS-CoV-2刺突S1结构域的宿主IgG和IgA的单克隆抗体，唾液中的检测限分别为4.8 ng/mL和13.3 ng/mL。对有症状的人类受试者（n = 14）的唾液样本进行的临床验证表明，该方法与聚合酶链反应（PCR）和商业酶联免疫吸附测定（ELISA）有很强的相关性，在感染检测方面实现了100%的灵敏度和100%的特异性，在宿主IgG和IgA检测方面分别实现了100%的灵敏度，特异性分别为91.7%和90.9%。这些结果突出了该新系统作为一种用于疫情监测和公共卫生管理的便携式诊断工具的潜在应用，这是为下一次全球大流行做准备的重要一步。
