Adsorption of bovine serum albumin in situ using SPR on modified thiol-PEG-acetic acid surface

Hydrophilic surfaces modified with polymer brushes have attracted significant attention due to their applications in biomedical fields, particularly for reducing nonspecific protein adsorption. In the current study, different concentrations of thiolpoly(ethylene glycol)-acetic acid (thiol-PEG-acetic acid) were used to modify gold surfaces using surface plasmon resonance (SPR), aiming to reduce non-specific protein adsorption. Different grafting densities were obtained by using different concentrations of thiol-PEG-acetic acid, and the results showed that the highest concentration of thiol-PEG-acetic acid produced a high thiol-PEG-acetic acid grafting density. All modified surfaces were characterized using advanced analytical techniques, including X-ray photoelectron spectroscopy (XPS), SPR, and water contact angle measurements. Furthermore, all surfaces were tested in a bovine serum albumin (BSA) solution. The study found that a low grafting density of thiol-PEG-acetic acid resulted in high protein adsorption on the modified gold surface.