title: A carbon nanotube-based high-sensitivity electrochemical immunosensor for rapid and portable detection of clenbuterol.
abstract: Carbon nanotubes have shown their unique advantages of mechanical, chemical and electronic properties in bioanalysis. We herein report a new method to efficiently and reproducibly prepare multi-walled carbon nanotubes (MWNTs)-protein sensing layers for electrochemical immunosensors. This method employs centrifugation to prepare a conjugate of MWNTs and goat anti mouse-immunoglobulin G (IgG) (secondary antibody). The conjugates were then deposited on screen-printed electrodes to form a nanostructured layer (MWNT-I layer). CLB monoclonal antibody was assembled through its binding to the secondary antibody. The MWNT-I layer-based electrodes were used for rapid and sensitive amperometric immunosensing detection of clenbuterol (CLB) in swine urine samples. Horseradish peroxidase-coupled CLB (CLB-HRP) competed with free CLB in the samples to bind the monoclonal antibody. It has shown significantly higher sensitivity and better reproducibility than the chemical conjugation method. This MWNT-based immunosensor is highly sensitive, leading to a limit of detection of 0.1 ng/mL within a rapid assay time of 16 min. Its sensitivity is at least 1 order of magnitude higher than that of a normal immunosensor (without MWNTs). The sensing device is portable with disposable screen-printed electrode, satisfactorily meeting the requirements for field detection of food security-related species.
authors.affiliation: Division of Chemistry and Ionizing Radiation Measurement Technology, Shanghai Institute of Measurement and Testing Technology, Shanghai 201203, PR China.
authors.forename: Gang
authors.initials: G
authors.lastname: Liu
authors.forename: Haode
authors.initials: H
authors.lastname: Chen
authors.forename: Hongzhen
authors.initials: H
authors.lastname: Peng
authors.forename: Shiping
authors.initials: S
authors.lastname: Song
authors.forename: Jimin
authors.initials: J
authors.lastname: Gao
authors.forename: Jianxin
authors.initials: J
authors.lastname: Lu
authors.forename: Min
authors.initials: M
authors.lastname: Ding
authors.forename: Lanying
authors.initials: L
authors.lastname: Li
authors.forename: Shuzhen
authors.initials: S
authors.lastname: Ren
authors.forename: Ziying
authors.initials: Z
authors.lastname: Zou
authors.forename: Chunhai
authors.initials: C
authors.lastname: Fan
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002976:Clenbuterol / Q000032:analysis*; D004350:Drug Residues / Q000032:analysis*; D055664:Electrochemical Techniques / Q000379:methods*; D007118:Immunoassay / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013552:Swine
chemical_list: D037742:Nanotubes, Carbon; D002976:Clenbuterol