title: Highly amplified electrochemiluminescence of peroxydisulfate using bienzyme functionalized palladium nanoparticles as labels for ultrasensitive immunoassay.
abstract: An immunosensor based on the electrochemiluminescence (ECL) of peroxydisulfate was firstly proposed by coupling the cooperation of two enzymes to in situ generate coreactant with palladium nanoparticles (PdNPs) as catalyst for the ECL reaction. PdNPs were previously synthesized, which successfully attached to functional carbon nanotubes (FCNTs), to bind the secondary antibody and bienzyme (horseradish peroxidase and glucose oxidase). Then the prepared bioconjugates were introduced to the electrode via sandwich immunoreactions. Accordingly, a dramatically amplified ECL signal was obtained for that GOD catalyzed glucose to produce H(2)O(2) which was subsequently reduced by HRP to in situ generate O(2), then PdNPs as catalyst for the ECL reaction of peroxydisulfate/O(2). The present immunosensor was used to detect α-1-fetoprotein (AFP) and showed a wide linear range of 1×10(-5)-100ng mL(-1), with a low detection limit of 3.3fg mL(-1)(S/N=3). This new signal amplification strategy for preparation of the ECL immunosensor could be easily realized and has a potential application in ultrasensitive bioassays.
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Huan
authors.initials: H
authors.lastname: Niu
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Chai
authors.forename: Li
authors.initials: L
authors.lastname: Mao
authors.forename: Huijing
authors.initials: H
authors.lastname: Liu
authors.forename: Yaling
authors.initials: Y
authors.lastname: Cao
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods; D008163:Luminescent Measurements / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D037742:Nanotubes, Carbon / Q000737:chemistry / Q000648:ultrastructure; D010165:Palladium / Q000737:chemistry*; D010545:Peroxides / Q000737:chemistry; D012680:Sensitivity and Specificity; D013431:Sulfates / Q000737:chemistry; D000509:alpha-Fetoproteins / Q000032:analysis* / Q000276:immunology
chemical_list: D037742:Nanotubes, Carbon; D010545:Peroxides; D013431:Sulfates; D000509:alpha-Fetoproteins; D010165:Palladium