Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Anal Chem. 2021 Nov 9;93(44):14685-14693. doi: 10.1021/acs.analchem.1c02889. Epub 2021 Oct 26.
To develop better analytical approaches for future global pandemics, it is widely recognized that sensing materials are necessary that enable molecular recognition and sensor assay development on a much faster scale than currently possible. Previously developed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) point-of-care devices are based on the specific molecular recognition using subunit protein antibodies and protein receptors that selectively capture the viral proteins. However, these necessarily involve complex and lengthy development and processing times and are notoriously prone to a loss of biological activity upon sensor immobilization and device interfacing, potentially limiting their use in applications at scale. Here, we report a synthetic strategy for nanoparticle corona interfaces that enables the molecular recognition of SARS-CoV-2 proteins without any antibody and receptor design. Our nanosensor constructs consist of poly(ethylene glycol) (PEG)─phospholipid heteropolymers adsorbed onto near-infrared (nIR) fluorescent single-walled carbon nanotubes (SWCNTs) that recognize the nucleocapsid (N) and spike (S) protein of SARS-CoV-2 using unique three-dimensional (3D) nanosensor interfaces. This results in rapid and label-free nIR fluorescence detection. This antibody-free nanosensor shows up to 50% sensor responses within 5 min of viral protein injections with limit of detection (LOD) values of 48 fM and 350 pM for N and S proteins, respectively. Finally, we demonstrate instrumentation based on a fiber-optic platform that interfaces the advantages of antibody-free molecular recognition and biofluid compatibility in human saliva conditions.
为了开发用于未来全球大流行的更好的分析方法，人们普遍认识到，需要能够在比目前更快的规模上进行分子识别和传感器分析的传感材料。以前开发的用于严重急性呼吸系统综合征冠状病毒 2（SARS-CoV-2）即时检测的设备是基于使用亚基蛋白抗体和蛋白质受体进行特定分子识别，这些抗体和蛋白质受体选择性地捕获病毒蛋白。然而，这些方法必然涉及复杂和冗长的开发和处理时间，并且众所周知，在传感器固定化和器件接口化过程中，生物活性容易丧失，这可能限制了它们在大规模应用中的使用。在这里，我们报告了一种用于纳米粒子冠状界面的合成策略，该策略能够实现对 SARS-CoV-2 蛋白的分子识别，而无需任何抗体和受体设计。我们的纳米传感器结构由聚乙二醇（PEG）-磷脂杂聚物组成，吸附在近红外（nIR）荧光单壁碳纳米管（SWCNT）上，该杂聚物使用独特的三维（3D）纳米传感器界面识别 SARS-CoV-2 的核衣壳（N）和刺突（S）蛋白。这导致快速且无标记的 nIR 荧光检测。这种无抗体的纳米传感器在病毒蛋白注射后 5 分钟内显示出高达 50%的传感器响应，其对 N 和 S 蛋白的检测限（LOD）值分别为 48 fM 和 350 pM。最后，我们展示了基于光纤平台的仪器，该仪器结合了无抗体分子识别和生物流体相容性的优点，适用于人类唾液条件。
