Terahertz and Infrared Spectroscopy of SARS-CoV-2 Spike Protein

Spectral properties of S and S1 spike proteins were studied using vibration spectroscopy methods. Also, vibration signatures of amino acids that make up the RGD, the part of S1 protein responsible for adhesion, were studied by Terahertz (THz) time-domain, Infrared (IR) and Raman spectroscopies in the low-frequency and in the fingerprint. THz metamaterials have been developed that increase the sensitivity of THz spectroscopy to the presence of both proteins. We have studied the spectra of amino acids, which play a role in the adhesion of proteins, on the metal surfaces of metamaterials, aluminum, and gold. Spectral differences were found between S and S1 proteins of SARS-CoV-2. The spectral differences between amino acids prepared in the form of thin films and in the form of bulk sample are discussed.