title: [Oriented immobilization of human IgG by protein A on imaging ellipsometry biosensor].
abstract: The biosensor based on optical imaging ellipsometry, can be used to detect directly, without labeling, the surface concentration of biomolecules on solid surface. The feasibility of using protein A to immobilize antibody on the silicon surface of the imaging ellipsometry biosensor was investigated in this study. The results showed that the anti-IgG immobilized by the protein A on silicon surface could bind effectively human IgG, and the human IgG immobilized on silicon surface by protein A bound more polyclonal antibody molecules than that immobilized on silicon surface directly, suggesting that protein A might block the surface to prevent the absorption of human IgG on surface directly, which might compromise its native configuration. The silicon surface modified with protein A is expected to be used to immobilize a variety of antibodies, as protein A can bind selectively the Fc regions of many mammalian IgG. The combination of imaging ellipsometry and the protein A surface modification has the potential to be developed into immunoassays of high sensitivity.
authors.affiliation: National Microgravity Laboratory, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080, China.
authors.forename: Yan-Li
authors.initials: YL
authors.lastname: Meng
authors.forename: Zhan-Hui
authors.initials: ZH
authors.lastname: Wang
authors.forename: Gang
authors.initials: G
authors.lastname: Jin
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007074:Immunoglobulin G / Q000737:chemistry*; D013205:Staphylococcal Protein A / Q000737:chemistry*
chemical_list: D007074:Immunoglobulin G; D013205:Staphylococcal Protein A