Ultrasensitive electrochemical immunoassay based on graphene oxide-Ag composites for rapid determination of clenbuterol

作者:Bai, Jing; Lai, Yanjun; Jiang, Dawei; Zeng, Yanbo; Xian, Yuezhong*; Xiao, Fei; Zhang, Ningdan; Hou, Jie; Jin, Litong
来源:Analyst, 2012, 137(18): 4349-4355.
DOI:10.1039/c2an35473j

摘要

We report the development of an ultrasensitive amperometric biosensor based on Ag nanoparticles-decorated graphene oxide nanosheets (GO) (Ag-GO) for the rapid detection of clenbuterol (CLB). The morphology and structure of the Ag-GO labeled CLB (Ag-GO-CLB) were characterized by transmission electron microscope (TEM), atomic force microscope (AFM), and ultraviolet-visible spectroscope (UV-vis). The immunosensor was prepared by covalently immobilizing capture antibodies on a multi-walled carbon nanotubes-modified glassy carbon electrode. Through competitive immunoreactions, the Ag-GO-CLB nanocomposites were captured on the immunosensor and the silver was measured by positive differential pulse voltammetry (DPV) in KCl solution for the detection of antigen. The experimental results show a linear response over the range from 0.01 to 10.0 ng mL(-1) with a lower detection limit of 6.8 pg mL(-1) (signal-to-noise ratio of 3). The Ag-GO based immunosensor offers a simple and convenient route for metal-immunoassay labels, which can avoid the complicated and time-consuming dissolving of metal component for ultrasensitive determination. Moreover, the electrochemical immunoassay shows acceptable specificity and stability and is suitable for the determination of CLB in real samples.