title: A sandwich-type immunosensor using Pd-Pt nanocrystals as labels for sensitive detection of human tissue polypeptide antigen.
abstract: A sandwich-type immunosensor was developed for the detection of human tissue polypeptide antigen (hTPA). In this work, a graphene sheet (GS) was synthesized to modify the surface of a glassy carbon electrode (GCE), and Pd-Pt bimetallic nanocrystals were used as secondary-antibody (Ab2) labels for the fabrication of the immunosensor. The amperometric response of the immunosensor for catalyzing hydrogen peroxide (H2O2) was recorded. And electrochemical impedance spectroscopy was used to characterize the fabrication process of the immunosensor. The anti-human tissue polypeptide antigen primary antibody (Ab1) was immobilized onto the GS modified GCE via cross-linking with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide (EDC/NHS). With Ab1 immobilized onto the GS modified GCE and Ab2 linked on Pd-Pt bimetallic nanocrystals, the immunosensor demonstrated a wide linear range (0.0050-15 ng ml(-1)), a low detection limit (1.2 pg ml(-1)), good reproducibility, good selectivity and acceptable stability. This design strategy may provide many potential applications in the detection of other cancer biomarkers.
authors.affiliation: Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, People's Republic of China.
authors.forename: Yaoguang
authors.initials: Y
authors.lastname: Wang
authors.forename: Qin
authors.initials: Q
authors.lastname: Wei
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Dan
authors.initials: D
authors.lastname: Wu
authors.forename: Hongmin
authors.initials: H
authors.lastname: Ma
authors.forename: Aiping
authors.initials: A
authors.lastname: Guo
authors.forename: Bin
authors.initials: B
authors.lastname: Du
mesh_terms: D055910:Antibodies, Immobilized; D015374:Biosensing Techniques / Q000295:instrumentation*; D055664:Electrochemical Techniques; D006108:Graphite; D006801:Humans; D007118:Immunoassay / Q000379:methods; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D036103:Nanotechnology; D010165:Palladium; D010984:Platinum; D015203:Reproducibility of Results; D019396:Tissue Polypeptide Antigen / Q000032:analysis* / Q000097:blood
chemical_list: D055910:Antibodies, Immobilized; D019396:Tissue Polypeptide Antigen; D010984:Platinum; D010165:Palladium; D006108:Graphite