title: Highly stable electrochemical immunosensor for carcinoembryonic antigen.
abstract: The long-term stability of sensing interfaces is an important issue in biosensor fabrication. A novel stable gold nanoparticle (AuNP)-modified glassy carbon (GC) electrode interface (GC-Ph-AuNP)-based biosensor for detecting carcinoembryonic antigen (CEA) was developed. GC electrodes were modified with 1,4-phenylenediamine to form a stable layer, and then AuNPs were bound onto the GC electrodes through CAu bonds. Anti-CEA was directly adsorbed on AuNPs fixed on the GC electrode. The linear range of the immunosensor was from 10 fg to 100 ng mL(-1) with a detection limit of 3 fg mL(-1) (S/N=3). The current of the immunosensor was increased by 4% after one month. The GC-Ph-AuNP immunosensor showed high sensitivity, a wide linear range, low detection limit, and good selectivity and stability. The immobilization method of the immunosensor could be widely applied to construct other immunosensors.
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing 100048, China.
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Sun
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing 100048, China. Electronic address: mazhanfang@yahoo.com.
authors.forename: Zhanfang
authors.initials: Z
authors.lastname: Ma
mesh_terms: D055910:Antibodies, Immobilized; D015374:Biosensing Techniques / Q000379:methods* / Q000706:statistics & numerical data; D002272:Carcinoembryonic Antigen / Q000032:analysis* / Q000276:immunology; D055664:Electrochemical Techniques; D006046:Gold; D006801:Humans; D007118:Immunoassay / Q000379:methods / Q000706:statistics & numerical data; D057230:Limit of Detection; D053768:Metal Nanoparticles; D012680:Sensitivity and Specificity
chemical_list: D055910:Antibodies, Immobilized; D002272:Carcinoembryonic Antigen; D006046:Gold