title: Protein A immunosensor for the detection of immunoglobulin G by impedance spectroscopy.
abstract: A novel highly sensitive electrochemical impedimetric Protein A immunosensor for the determination of immunoglobulin G (IgG) was developed by immobilization of Protein A within a newly synthesized, and characterized polymer, poly(maleicanhydride-alt-decene-1). TiO2 nanoparticles (10-30 nm) were synthesized, characterized with X-ray diffraction, transmission electron microscopy and Brunauer-Emmett-Teller surface analysis. The electron transfer between IgG and the poly(maleicanhydride-alt-decene-1)-TiO2-Protein A is quasireversible with a formal potential of 225 mV vs Ag|AgCl. The response of the poly(maleicanhydride-alt-decene-1)-TiO2-Protein A immunosensor was proportional to IgG concentration with a correlation coefficient of 0.9963. The detection limit and linear range was 0.57 ng mL(-1) and 0.0062-500 μg mL(-1), respectively. Impedance measurments showed that synthesized TiO2 nanoparticles have better conducting properties compared with commercial degussa P25 TiO2 nanoparticles. The nonspecific binding of anti-MBP was 10 %. The label-free impedimetric immunosensor provided a simple and sensitive detection method for the specific determination of IgG in human serum.
authors.affiliation: Department of Chemistry, Science Faculty, Ankara University, Tandoğan, Ankara, 06100, Turkey.
authors.forename: Burak
authors.initials: B
authors.lastname: Derkus
authors.forename: Kaan
authors.initials: K
authors.lastname: Cebesoy Emregul
authors.forename: Hidayet
authors.initials: H
authors.lastname: Mazi
authors.forename: Emel
authors.initials: E
authors.lastname: Emregul
authors.forename: Tugrul
authors.initials: T
authors.lastname: Yumak
authors.forename: Ali
authors.initials: A
authors.lastname: Sinag
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D000090266:Chromobox Protein Homolog 5; D058266:Dielectric Spectroscopy / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis* / Q000097:blood; D053758:Nanoparticles / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D012680:Sensitivity and Specificity; D013205:Staphylococcal Protein A / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry
chemical_list: C000715594:CBX5 protein, human; D007074:Immunoglobulin G; D011108:Polymers; D013205:Staphylococcal Protein A; D000090266:Chromobox Protein Homolog 5; C009495:titanium dioxide; D014025:Titanium