Unravelling Nonspecific Adsorption of Complex Protein Mixture on Surfaces with SPR and MS

Characterization of protein adsorption to surfaces has implications from biosensing to protective biocoatings. While research studies have principally focused on determining the magnitude of protein adsorption to surfaces, the proteins involved in the process remains only broadly identified and has not been investigated on several surfaces. To further elucidate the nonspecific adsorption process of serum to surfaces, surface plasmon resonance (SPR) and matrix assisted laser desorption ionization mass spectrometry (MALDI-MS) were used in combination to obtain quantitative and qualitative information about the process of protein adsorption to surfaces. To validate the technique, crude serum was nonspecifically adsorbed on four self-assembled monolayer (SAM) on gold: 16-mercaptohexadecanoic acid (16-MHA), 11-mercaptoundecane(ethylene glycol)3-COOH (PEG), 3-MPA-LHDLHD-OH, and 3-MPA-HHHDD-OH. Direct MS analysis of the nonspecifically adsorbed proteins suggested the presence of a variety of protein (BSA, IgG, a...