title: Site-directed immobilization of antibody using EDC-NHS-activated protein A on a bimetallic-based surface plasmon resonance chip.
abstract: The characteristics of a waveguide-coupled bimetallic surface plasmon resonance (WcBiM SPR) sensor using (3-dimethylaminopropyl)-3-ethylcarbodiimide(EDC)-N-hydroxysuccinimide(NHS)-activated protein A was investigated, and the detection of IgG using the EDC-NHS-activated protein A was studied in comparison with protein A and a self-assembled monolayer (SAM). The WcBiM sensor, which has a narrower full width at half maximum (FWHM) and a steeper slope, was selected since it leads to a larger change in the reflectance in the intensity detection mode. A preparation of the EDC-NHS-activated protein A for site-directed immobilization of antibodies was relative easily compared to the engineered protein G and A. In antigen-antibody interactions, the response to IgG at the concentrations of 50, 100, and 150 ng/ml was investigated. The results showed that the sensitivity of the WcBiM sensor using the EDC-NHS-activated protein A, protein A, and SAM was 0.0185 [%/(ng/ml)], 0.0065 [%/(ng/ml)], and 0.0101 [%/(ng/ml)], respectively. The lowest detectable concentrations of IgG with the EDC-NHS-activated protein A, protein A, and SAM were 4.27, 12.83, and 8.24 ng/ml, respectively. Therefore, the increased sensitivity and lower detection capability of the WcBiM SPR chip with the EDC-NHS-activated protein A suggests that it could be used in early diagnosis where the trace level concentrations of biomolecules should be detected.
authors.forename: Young-Soo
authors.initials: YS
authors.lastname: Sohn
authors.forename: Yeon Kyung
authors.initials: YK
authors.lastname: Lee
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry* / Q000378:metabolism; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002234:Carbodiimides / Q000737:chemistry*; D004867:Equipment Design; D007074:Immunoglobulin G / Q000737:chemistry / Q000378:metabolism; D013205:Staphylococcal Protein A / Q000737:chemistry*; D013388:Succinimides / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods
chemical_list: C518491:1-ethyl-3-(3-(diethylamino)propyl)carbodiimide; D055910:Antibodies, Immobilized; D002234:Carbodiimides; D007074:Immunoglobulin G; D013205:Staphylococcal Protein A; D013388:Succinimides; C001426:N-hydroxysuccinimide