A novel electrochemical immunosensor for highly sensitive detection of aflatoxin B-1 in corn using single-walled carbon nanotubes/chitosan

卷:192

Zhang, Xian ; Li, Chao-Rui ; Wang, Wei-Cheng ; Xue, Jian ; Huang, Ya-Ling ; Yang, Xian-Xian ; Tan, Bin ; Zhou, Xi-Peng ; Shao, Chuang ; Ding, Shi-Jia ; Qiu, Jing-Fu

Chongqing Med Univ

关键词: Aflatoxin B-1;    Electrochemical immunosensor;    Sensitive detection;    Single-walled carbon nanotubes/chitosan;    Corn powder;   

DOI  :  10.1016/j.foodchem.2015.06.044

学科分类：食品科学和技术

【 摘 要 】

A sensitive electrochemical immunosensor for aflatoxin B-1 (AFB(1)) detection based on single-walled carbon nanotubes/chitosan was presented. The immunosensor was based on an indirect competitive binding to a fixed amount of anti-AFB(1) between free AFB(1) and AFB(1)-bovine serum albumin, which conjugate immobilized on covalently functionalized nanotubes/chitosan laid on the glass carbon electrode. Then, the anti-mouse immunoglobulin G secondary antibody labeled with alkaline phosphatase was bound to the electrode surface through reacting with primary antibody. Finally, alkaline phosphatase catalyzes the hydrolysis of the substrate (x-naphthyl phosphate, which produced electrochemical signal. Compared with conventional methods, the established immunosensor was more sensitive and simple. Under optimal conditions, this method could quantitatively detect AFB(1) from 0.01 to 100 ng mL(-1) with a detection limit of 3.5 pg mL(-1). Moreover, the immunosensor was successfully applied to assay AFB(1) in corn powder, which showed good correlation with the results obtained from high performance liquid chromatography. (C) 2015 Elsevier Ltd. All rights reserved.