title: A sensitive label-free amperometric immunosensor for alpha-fetoprotein based on gold nanorods with different aspect ratio.
abstract: A simple and accurate label-free amperometric immunosensor for α-fetoprotein (AFP) detection is developed based on gold nanorods (GNRs) with different aspect ratio and compared with gold particles (GNPs). The positively charged GNRs and GNPs due to the surface immobilized cetyltrimethyl ammonium bromide (CTAB) can adsorb the negatively charged AFP antibody (Ab) directly. The presence of the GNRs not only enhanced the immobilized amount of biomolecules, but also improved the electrochemical properties of the immunosensor. With the aid of GNRs, the electrochemical signal was greatly enhanced in comparison with GNPs. Under optimal conditions, the proposed immunosensor could detect AFP in a linear range from 0.1 to 200 ng/mL with a detection limit of 0.04 ng/mL (signal-to-noise ratio = 3), and it also possessed good reproducibility and storage stability. Moreover, the detection of AFP in five human serum samples also showed satisfactory accuracy. The proposed methodology was potentially attractive for clinical immunoassay.
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, P. R. China.
authors.forename: Chunyang
authors.initials: C
authors.lastname: Zhou
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, P. R. China.
authors.forename: Dali
authors.initials: D
authors.lastname: Liu
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, P. R. China.
authors.forename: Lin
authors.initials: L
authors.lastname: Xu
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, P. R. China.
authors.forename: Qingling
authors.initials: Q
authors.lastname: Li
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, P. R. China.
authors.forename: Jian
authors.initials: J
authors.lastname: Song
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, P. R. China.
authors.forename: Sai
authors.initials: S
authors.lastname: Xu
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, P. R. China.
authors.forename: Ruiqing
authors.initials: R
authors.lastname: Xing
authors.affiliation: 1] State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, P. R. China [2] The State Key Laboratory of Bioelectronics, Southeast University, 210096 P. R. China.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Song
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry / Q000276:immunology; D015374:Biosensing Techniques; D055664:Electrochemical Techniques; D005295:Ferrocyanides / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D013696:Temperature; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D055910:Antibodies, Immobilized; D005295:Ferrocyanides; D000509:alpha-Fetoproteins; C116383:ferrocyn; D006046:Gold