Spectroscopic Characterization and Oxidation on Catalytic Surfaces of Amino Acids Present in Viral Proteins

Abstract

The outbreak of COVID-19 and its widespread transmission across the world has reasserted the need for understanding viruses and, consequently, the interactions of large biomolecules and ways to characterize them. This work studies the interactions of amino acids present in virus proteins with surfaces from a catalysis point of view. A review of inventions and patents in the field shows the use of metal and metal oxide catalysts in deactivating viruses; however, the mechanism of this process and tools to characterize biomolecules chemistry changes on surfaces are lacking. Towards the goal of devising an effective and simple method to achieve and monitor biomolecules chemical changes on catalytic surfaces, in situ FTIR combined with 2D-COS and online MS was employed to study the temperature programmed oxidation (TPO) of structurally related amino acids on α-alumina (α-Al2O3) and α-Al2O3 supported silver catalyst (Ag/α-Al2O3) surfaces. The samples were analyzed by TGA to study their decomposition temperature profiles and to ascertain kinetic parameters such as apparent activation energies. Bond dissociation energy values of the amino acids along with 2D-COS and gas product formation as monitored by online MS during TPO were studied to determine possible reaction pathways and products. The amino acids were shown to oxidize more effectively on Ag(30%)/α-Al2O3 catalyst, with reactions occurring at lower temperatures than those observed on α-Al2O3 and with primarily formation of COx, H2O, and NH3 in the gas phase. TGA kinetic studies showed a reduction of activation energy on the catalyst for all studied amino acids, suggesting catalytic activity on silver, but thermal decomposition on α-Al2O3. FTIR/2D-COS/MS provided a quick, qualitative means of tracking and understanding changes in real time and determining functional group reactivity. These results provide the basis for in situ and real time characterization of larger biomolecules and encourage future studies on the use of metal and metal oxide surfaces for virus deactivation.