A Four-Channel Surface Plasmon Resonance Sensor Functionalized Online for Simultaneous Detections of Anti-SARS-CoV-2 Antibody, Free Viral Particles, and Neutralized Viral Particles

Abstract

Current tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detect either the constituent nucleic acids/proteins of the viral particles or antibodies specific to the virus, but cannot provide information about viral neutralization by an antibody and the efficacy of an antibody. Such information is important about individuals' vulnerability to severe symptoms or their likelihood of showing no symptoms. We immobilized online SARS-CoV-2 spike (S1) protein and angiotensin-converting enzyme 2 (ACE2) into separate surface plasmon resonance (SPR) channels of a tris-nitrilotriacetic acid (tris-NTA) chip to simultaneously detect the anti-S1 antibody and viral particles in serum samples. In addition, with a high-molecular-weightcutoff filter, we separated the neutralized viral particles from the free antibody molecules and used a sensing channel immobilized with Protein G to determine antibody-neutralized viral particles. The optimal density of probe molecules in each fluidic channel can be precisely controlled through the closure and opening of the specific ports. By utilizing the high surface density of ACE2, multiple assays can be carried out without regenerations. These three species can be determined with a short analysis time (<12 min per assay) and excellent sensor-to-sensor/cycle-to-cycle reproducibility (RSD < 5%). When coupled with an autosampler, continuous assays can be performed in an unattended manner at a single chip for up to 6 days. Such a sensor capable of assaying serum samples containing the three species at different levels provides additional insights into the disease status and immunity of persons being tested, which should be helpful for containing the SARS-CoV-2 spread during the era of incessant viral mutations.

Large-scale validation of a plasmonic sensor for SARS-CoV-2 pseudo-neutralization with a cohort of food and retail workers

“…[17][18][19][20][21][22][23] Quantitative determination of biomolecular interactions is a hallmark of SPR sensing, which has been used to determine antibody affinity 24,25 and other biomolecular binding information, 26,27 and these properties were valuable during the COVID-19 pandemic. Recently, a promising SPR platform was developed to detect antibodies, viral particles and neutralized viral particles, 28 providing an all-in-one sensor to address the key questions related to SARS-CoV-2 infection and the pandemic response. Similarly, SPR sensing has been applied to small molecule screening for discovery of putative therapeutic inhibitors such as peptides, 29 cannabinoids, 30 or other small molecule inhibitors.…”

Liposome-based high-throughput and point-of-care assays toward the quick, simple, and sensitive detection of neutralizing antibodies against SARS-CoV-2 in patient sera

“…Other sensing strategies have been investigated in pursuit of shorter assay times, increased throughput, and improved sensitivity. A flow-based chemiluminescence microarray immunoassay could detect nAbs in blood samples in just 7 min [15], while a four-channel SPR sensor enabled simultaneous detection of anti-S1 antibodies as well as free and neutralized virus particles [16]. The use of a Tri-part split-NanoLuc® facilitated a homogeneous neutralization test [17] and the use of Luminex beads holds the potential for multiplexing [18].…”

Large-scale validation of a plasmonic sensor for SARS-CoV-2 pseudo-neutralization with a cohort of food and retail workers

“…Quantitative determination of biomolecular interactions is a hallmark of SPR sensing, which has been used to determine antibody affinity 24,25 and other biomolecular binding information 26,27 , and these properties were valuable during the COVID-19 pandemic. Recently, a promising SPR platform was developed to detect antibodies, viral particles and neutralized viral particles 28 , providing an all-in-one sensor to address the key questions related to SARS-CoV-2 infection and the pandemic response.…”