Mirza Asma, Marino John, Aguren Jerry, Bruno John G
Steradian Technologies, Inc., 2450 Holcombe Street. Suite J, Houston, TX, 77021, USA.
Nanohmics, Inc., 6201 E. Oltorf Street. Suite 400, Austin, TX, 78741, USA.
J Fluoresc. 2025 Feb 10. doi: 10.1007/s10895-025-04163-8.
Rapid detection of respiratory diseases using a noninvasive bind-and-detect breath test could shift the future of rapid diagnostics. Commercially available biotinylated anti-SARS-CoV-2 spike (S) protein antibody was conjugated to streptavidin-coated quantum dots, purified, and adsorbed onto magnetic-graphene oxide (M-GO) flakes to quench the conjugate. When inactivated SARS-CoV-2 was added at increasing levels, the antibody-quantum dot conjugates desorbed from the M-GO as a function of virus concentration with an apparent limit of detection ~ 9,600 inactivated virus particles within 2-5 min in phosphate-buffered saline (PBS) plus 10 mM Mg assessed by a spectrofluorometer. A similar fluorescence response was obtained using a published biotinylated DNA aptamer sequence designated MSA52 and inactivated SARS-CoV-2 in PBS plus 5 mM Mg. Concentrations of Mg greater than 5 mM diminished the aptamer magnetic-graphene oxide desorption (M-GOD) assay performance, perhaps by altering the aptamer's 3-dimensional conformation and ability to bind the virus. As reported previously, the MSA52 aptamer assay demonstrated reasonable specificity for variants of SARS-CoV-2 and significantly less intense detection of inactivated Influenza A and Respiratory Syncytial Virus (RSV) in the M-GOD assay format. This rapid and sensitive detection of inactivated SARS-CoV-2 in clear PBS buffer bodes well for the ultimate goal of rapid homogeneous bind-and-detect detection of COVID and other viral respiratory pathogens in human breath condensates and other easily accessible body fluids.
使用非侵入性结合检测呼气试验快速检测呼吸道疾病可能会改变快速诊断的未来。将市售的生物素化抗SARS-CoV-2刺突（S）蛋白抗体与链霉亲和素包被的量子点偶联，纯化后吸附到磁性氧化石墨烯（M-GO）薄片上以淬灭偶联物。当以递增水平添加灭活的SARS-CoV-2时，抗体-量子点偶联物会从M-GO上解吸，解吸量是病毒浓度的函数，在含有10 mM Mg的磷酸盐缓冲盐水（PBS）中，用荧光分光光度计评估，在2-5分钟内的检测限约为9600个灭活病毒颗粒。使用已发表的名为MSA52的生物素化DNA适体序列和在含有5 mM Mg的PBS中的灭活SARS-CoV-2也获得了类似的荧光响应。Mg浓度大于5 mM会降低适体磁性氧化石墨烯解吸（M-GOD）分析性能，这可能是通过改变适体的三维构象及其结合病毒的能力实现的。如先前报道，MSA52适体分析对SARS-CoV-2变体显示出合理的特异性，并且在M-GOD分析形式中对灭活的甲型流感病毒和呼吸道合胞病毒（RSV）的检测强度明显较低。在清澈的PBS缓冲液中对灭活的SARS-CoV-2进行这种快速灵敏的检测，对于在人呼气冷凝物和其他易于获取的体液中快速均相结合检测COVID和其他病毒性呼吸道病原体的最终目标来说是个好兆头。
