Characterization of protein adsorption of amino acid conjugated self-assembled molecules modified SiO2 surfaces by QCM

Protein adsorption has a crucial effect on biocompatibility during the interaction of biomaterial surfaces and the biological environment. It is significant to understand and control the interactions among biomaterials and proteins for several biomedical applications. Surface engineering plays a significant role to determine biocompatibility via tuning the effects directly on proteins. In this study, amino acid (histidine and leucine) conjugated self-assembled molecules (SAMs) were synthesized and used to modify silicon dioxide (SiO2) surfaces to investigate protein adsorption behavior. SiO2 surfaces were modified with (3-aminopropyl) triethoxysilane (APTES) conjugated histidine and leucine amino acids. Modified SiO2 surfaces were characterized by water contact angle measurements (WCA) and X-Ray Photoelectron Spectroscopy (XPS) analysis. Protein adsorption [Human Serum Albumin (HSA), fibrinogen, and Immunoglobulin G (IgG)] on SiO2 coated crystals was investigated in situ by using Quartz Crystal Microbalance (QCM) biosensor. According to the results, model proteins have shown different selectivity to the amino acid conjugated SiO2 coated crystals depending on the type of the amino acids and concentration. Consequently, this controlled chemistry on the surface of biomaterials has a great potential to manipulate protein adsorption and enhance the biocompatibility of biomaterials for various biomedical applications.