Role of salts on BSA adsorption on stainless steel in aqueous solutions. I. FT‐IRRAS and XPS characterization

Abstract

The understanding of protein interaction with metal surfaces has become a key question for the use of materials in medicine, in the food industry or in marine environment in connection with the process of biofouling. However, the role of the various salts present in natural seawater has never been systematically investigated. In the present work, we studied the adsorption of a protein, bovine serum albumin (BSA), on stainless-steel surfaces in artificial seawater and in aqueous solutions containing NaCl, NaCl + CaCl 2 and NaCl + MgCl 2 , the total concentration of salts being identical to that of the natural seawater (36 g l −1 ); the BSA concentration was fixed at 20 mg l −1 . After rinsing and drying, the surface was analysed by Fourier transform infrared reflection-adsorption spectroscopy (FT-IRRAS) and x-ray photoelectron spectroscopy (XPS). After immersion in aqueous solutions containing NaCl or NaCl + CaCl 2 and rinsing in saline solutions, the amount of adsorbed BSA is small. It increases by almost one order of magnitude if the immersion is performed in NaCl + MgCl 2 aqueous solution; after 24 h of immersion it reaches a saturation value very close to that attained in natural seawater. At saturation of the stainless-steel surface by the protein, the XPS metal signals were still detected, suggesting that the protein layer is heterogeneous, leaving patches of the surface almost uncovered. The amount of adsorbed BSA is reduced by almost one order of magnitude when the samples are rinsed in pure, demineralized water due to the dissolution of Mg 2+ cations and the elimination of loosely adsorbed proteins. The presence of Mg 2+ cations within the BSA layer is confirmed by angle-resolved XPS analyses.

Evaluation of adhesion force between functionalized microbeads and protein-coated stainless steel using shear-flow-induced detachment

“…4A). These peaks are representative of chemical groups present in BSA and/or in glutaraldehyde [37]. The N1s signal was composed of two peaks (Fig.…”

Bovine serum albumin adsorption onto 316L stainless steel and alumina: a comparative study using depletion, protein radiolabeling, quartz crystal microbalance and atomic force microscopy

“…However, since there are divalent cations (Mg 2+ and Ca 2+ ) present in the solvent (HBSS), the interaction of BSA molecules with the negative surfaces may occur through the bridging of these cations. [36] The lower surface energy and polarity of the SS plates indicate that they are more hydrophobic than the alumina plates. In general, proteins with low conformational stability ('soft proteins'), such as BSA, [37,38] adsorb to either hydrophilic or hydrophobic surfaces.…”

Graft photopolymerization of polyethylene glycol monoacrylate (PEGA) on poly(methyl methacrylate) (PMMA) films to prevent BSA adsorption

“…[1,2] Since protein adsorption constitutes the first step in biofilm formation, several approaches are proposed in the literature to prevent it. [3] Indeed, Polyethylene glycol (PEG) based compounds extensively proved their remarkable antifouling properties.…”