Immobilization of Protein A on SAMS for the elaboration of immunosensors
Binary mixtures of 11-mercaptoundecanoic acid (MUA) and other thiols of various lengths and terminal functions were chemisorbed on gold-coated surfaces via S-Au bonds to form mixed self-assembled monolayers (SAMs). Several values of the inole fraction of MUA in the thiol mixtures were tested and the structure and composition of the resulted thin films were characterized by X-ray photoelectron spectroscopy (XPS) and polarization modulation infrared reflection-absorption spectroscopy (PM-IRRAS). The results made it clear that co-adsorption of MUA with thiols of similar chain length led to well-ordered monolayers whereas the co-adsorption of MUA with shorter thiols yielded less crystalline-like thin films, but with more reactive carboxylic acid terminal groups. This criterion appeared decisive for efficient covalent binding of Stapkylococcus aureus Protein A (PrA), a protein that displays high affinity for the constant fragment (Fc) of antibodies of the IgG type from various mammal species. The ability of immobilized Protein A to recognize and bind a model IgG appeared to be optimal for the mixed SAM of MUA and the short-chain, omega-hydroxythiot 6-mercaptohexanol in the proportion 1-3. (c) 2006 Elsevier B.V. All rights reserved.
Keyword(s)
PM IRRAS, Antibody, Protein A, Gold, Self assembled monolayers
Briand Elisabeth, Salmain Michèle, Compere Chantal, Pradier Claire-Marie (2006). Immobilization of Protein A on SAMS for the elaboration of immunosensors. Colloids and Surfaces B: Biointerfaces. 53 (2). 215-224. https://doi.org/10.1016/j.colsurfb.2006.09.010, https://archimer.ifremer.fr/doc/00000/2222/