title: A nanowire-based label-free immunosensor: direct incorporation of a PSA antibody in electropolymerized polypyrrole.
abstract: We have suggested a novel method for the preparation of a label-free electrochemical immunosensor for the detection of prostate-specific antigen (PSA) as target marker for prostate cancer. Direct incorporation of PSA antibody (anti-PSA) into polypyrrole (Ppy) electropolymerized on a three-dimensional Au nanowire array has resulted in enhanced molecular interactions, ultimately leading to improved sensing performance. The electrochemical performance of the nanowire-based immunosensor array were characterized by (1) differential pulse voltammetry (DPV) to evaluate the specific recognition of PSA, (2) impedance and cyclic voltammetry to observe surface resistance and electroactivity, and (3) scanning electron microscopy (SEM) to demonstrate the three-dimensional architecture. The vertically-aligned geometric organization of Ppy provides a novel platform to improve the anti-PSA loading capacity. Overall, enhanced electrochemical performance of the proposed immunosensor has been demonstrated by its linear response over PSA concentrations ranging from 10 fg mL(-1) to 10 ng mL(-1) and a detection limit of 0.3 fg mL(-1), indicating that the strategy proposed here has great potential for clinical applications.
authors.affiliation: New Experimental Therapeutics Branch, National Cancer Center, 111 Jungbalsan-ro, Ilsandong-gu, Goyang, Gyeonggi-do 410-769, South Korea.
authors.forename: Jeong-Mi
authors.initials: JM
authors.lastname: Moon
authors.affiliation: New Experimental Therapeutics Branch, National Cancer Center, 111 Jungbalsan-ro, Ilsandong-gu, Goyang, Gyeonggi-do 410-769, South Korea.
authors.forename: Yon Hui
authors.initials: YH
authors.lastname: Kim
authors.affiliation: New Experimental Therapeutics Branch, National Cancer Center, 111 Jungbalsan-ro, Ilsandong-gu, Goyang, Gyeonggi-do 410-769, South Korea. Electronic address: yncho@ncc.re.kr.
authors.forename: Youngnam
authors.initials: Y
authors.lastname: Cho
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D058105:Polymerization; D011108:Polymers / Q000737:chemistry*; D017430:Prostate-Specific Antigen / Q000032:analysis / Q000097:blood*; D011758:Pyrroles / Q000737:chemistry*
chemical_list: D055910:Antibodies, Immobilized; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D017430:Prostate-Specific Antigen
keywords: Differential pulse voltammetry; Label-free immunosensor; Nanowire; Polypyrrole; Prostate-specific antigen