title: Sensitive electrochemical immunosensor for cancer biomarker with signal enhancement based on nitrodopamine-functionalized iron oxide nanoparticles.
abstract: A novel electrochemical immunosensor for sensitive detection of cancer biomarker prostate specific antigen (PSA) based on nitrodopamine (NDA) functionalized iron oxide nanoparticles (NDA-Fe(3)O(4)) is described. NDA-Fe(3)O(4) was used both for the immobilization of primary anti-PSA antibody (Ab(1)) and as secondary anti-PSA antibody (Ab(2)) label. For the preparation of the label, mediator thionine (TH) was first conjugated onto NDA-Fe(3)O(4) based on the amino groups of NDA, and then the amino group of TH was used to immobilize horseradish peroxidase (HRP) and Ab(2). Due to the high amount of NDA anchored onto Fe(3)O(4) surface, the loading of antibodies as well as mediator and enzyme onto NDA-Fe(3)O(4) was substantially increased, which increased the sensitivity of the immunosensor. The resulting immunosensor displayed a wide range of linear response (0.005-50 ng/mL), low detection limit (4 pg/mL), good reproducibility and stability. The immunosensor was used to detect the PSA contents in serum samples with satisfactory results.
authors.affiliation: School of Medical and Life Sciences, University of Jinan, Jinan 250022, PR China.
authors.forename: He
authors.initials: H
authors.lastname: Li
authors.forename: Qin
authors.initials: Q
authors.lastname: Wei
authors.forename: Gaolei
authors.initials: G
authors.lastname: Wang
authors.forename: Minghui
authors.initials: M
authors.lastname: Yang
authors.forename: Fengli
authors.initials: F
authors.lastname: Qu
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Qian
mesh_terms: D055910:Antibodies, Immobilized; D015374:Biosensing Techniques / Q000379:methods* / Q000706:statistics & numerical data; D001774:Blood Chemical Analysis / Q000379:methods / Q000706:statistics & numerical data; D004298:Dopamine / Q000031:analogs & derivatives; D055664:Electrochemical Techniques; D006801:Humans; D058185:Magnetite Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D008297:Male; D046529:Microscopy, Electron, Transmission; D055616:Microtechnology; D036103:Nanotechnology; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis
chemical_list: C403895:6-nitrodopamine; D055910:Antibodies, Immobilized; D058185:Magnetite Nanoparticles; D017430:Prostate-Specific Antigen; D004298:Dopamine