title: An electrochemical biosensor for alpha-fetoprotein based on carbon paste electrode constructed of room temperature ionic liquid and gold nanoparticles.
abstract: A novel and effective electrochemical immunosensor for the rapid determination of alpha-fetoprotein (AFP) based on carbon paste electrode (CPE) consisting of room temperature ionic liquid (RTIL) N-butylpyridinium hexafluorophosphate (BPPF(6)) and graphite. The surface of the CPE was modified with gold nanoparticles for the immobilization of the alpha-fetoprotein antibody (anti-AFP). By sandwiching the antigen between anti-AFP on the CPE modified with gold nanoparticles and the secondary antibody, polyclonal anti-human-AFP labeled with horseradish peroxidase (HRP-labeled anti-AFP), the immunoassay was established. The concentration of AFP was determined based on differential pulse voltammetry (DPV) signal, which was generated in the reaction between O-aminophenol (OAP) and H(2)O(2) catalyzed by HRP labeled on the sandwich immunosensor. AFP concentration could be measured in a linear range of 0.50-80.00 ng mL(-1) with a detection limit of 0.25 ng mL(-1). The immunosensor exhibited high sensitivity and good stability, and would be valuable for clinical assay of AFP.
authors.affiliation: The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, Beijing 100084, PR China.
authors.forename: Caifeng
authors.initials: C
authors.lastname: Ding
authors.forename: Fei
authors.initials: F
authors.lastname: Zhao
authors.forename: Rui
authors.initials: R
authors.lastname: Ren
authors.forename: Jin-Ming
authors.initials: JM
authors.lastname: Lin
mesh_terms: D000906:Antibodies; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002244:Carbon; D055664:Electrochemical Techniques / Q000295:instrumentation; D004566:Electrodes; D006046:Gold; D006735:Horseradish Peroxidase; D052578:Ionic Liquids; D053768:Metal Nanoparticles; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D000906:Antibodies; D052578:Ionic Liquids; D000509:alpha-Fetoproteins; D002244:Carbon; D006046:Gold; D006735:Horseradish Peroxidase