Design of engineered surfaces for prospective detection of SARS-CoV-2 using quartz crystal microbalance-based...

Rapid transmission of the severe acute respiratory syndrome coronavirus 2 has affected the whole world and forced it to a halt (lockdown). A fast and label-free detection method for the novel coronavirus needs to be developed along with the existing enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR)-based methods.

In this report, biophysical aspects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike glycoprotein are outlined based on its recent reported electron microscopy structure. Protein binding sites are analyzed theoretically, which consisted of hydrophobic and positive charged amino acid residues. Different strategies to form mixed self-assembled monolayers (SAMs) of hydrophobic (CH₃) and negatively charged (COOH) groups are discussed to be used for the specific and strong interactions with spike protein. Bio-interfacial interactions between the spike protein and device (sensor) surface and its implications toward designing suitable engineered surfaces are summarized.

Implementation of the engineered surfaces in quartz crystal microbalance (QCM)-based detection techniques for the diagnosis of the novel coronavirus from oral swab samples is highlighted. The proposed strategy can be explored for the label-free and real-time detection with sensitivity up to ng level. These engineered surfaces can be reused after desorption.