• 文献标题:   Voltammetric sandwich immunoassay for Cronobacter sakazakii using a screen-printed carbon electrode modified with horseradish peroxidase, reduced graphene oxide, thionine and gold nanoparticles
  • 文献类型:   Article
  • 作  者:   ZHU FJ, ZHAO GY, DOU WC
  • 作者关键词:   electrochemical immunoassay, foodborne pathogen, hrp, nanoparticlebased detection
  • 出版物名称:   MICROCHIMICA ACTA
  • ISSN:   0026-3672 EI 1436-5073
  • 通讯作者地址:   Zhejiang Gongshang Univ
  • 被引频次:   3
  • DOI:   10.1007/s00604-017-2572-x
  • 出版年:   2018

▎ 摘  要

The authors describe a sandwich-type of electrochemical immunoassay for rapid determination of the foodborne pathogen Cronobacter sakazakii (C. sakazakii). Polyclonal antibody against C. sakazakii (anti-C. sakazakii) and horseradish peroxidase were immobilized on a nanocomposite consisting of reduced graphene oxide, thionine and gold nanoparticles (AuNPs) that was placed on a screen-printed carbon electrode (SPCE). Thionine acts as an electron mediator which also shortens the electron transfer pathway from the conjugated HRP to the electrode surface and amplifies the electrochemical signal. The AuNPs, in turn, improve the electron transfer rate and increase the surface area for capturing antibody. The morphologies of the electrodes were characterized by means of field emission scanning electron microscopy. The electrochemical performance of the immunoassay was evaluated by cyclic voltammetry and differential pulse voltammetry. Under optimal experimental conditions, the electrochemical immunoassay, best operated at a woking potential of -0.18 V (vs. Ag/AgCl) and scan rate of 20 mV/s has a linear response that covers the 8.8 x 10(4) to 8.8 x 10(8) CFU.mL(-1) C. sakazakii concentration range, with a 1.0 x 10(4) CFU.mL(-1) detection limit (at an S/N ratio of 3). The assay was applied to the detemination of C. sakazakii in spiked infant milk powder and gave recoveries ranging from 92.0 to 105.7%.