Construction of Electrochemical Immunosensor Based on Gold-Nanoparticles/Carbon Nanotubes/Chitosan for Sensitive Determination of T-2 Toxin in Feed and Swine Meat

• Main Authors: Yanxin Wang, Liyun Zhang, Dapeng Peng, Shuyu Xie, Dongmei Chen, Yuanhu Pan, Yanfei Tao, Zonghui Yuan
• Format: Article
• Language: English
• Published: MDPI AG 2018-12-01
• Series: International Journal of Molecular Sciences
• Subjects: T-2 toxin; electrochemical immunosensor; gold nanoparticles/single-walled carbon nanotubes/chitosan; feed; swine meat
• Online Access: https://www.mdpi.com/1422-0067/19/12/3895

T-2 toxin (T-2) is one of major concern mycotoxins acknowledged as an unavoidable contaminant in human foods, animal feeds and also agriculture products. Thus, a facile and sensitive method is essential for accurate T-2 toxin detection. In our work, a specific electrochemical immunosensor based on gold nanoparticles/carboxylic group-functionalized single-walled carbon nanotubes/chitosan (AuNPs/cSWNTs/CS) composite was established. The mechanism of the electrochemical immunosensor was an indirect competitive binding to a given amount of anti-T-2 between free T-2 and T-2-bovine serum albumin, which was conjugated on covalently functionalized cSWNTs decorated on the glass carbon electrode. Afterwards, the alkaline phosphatase labeled anti-mouse secondary antibody was bound to the electrode surface by reacting with the primary antibody. Lastly, alkaline phosphatase catalyzed the hydrolysis of the substrate α-naphthyl phosphate, which produced an electrochemical signal. Compared with conventional methods, the established immunosensor was more sensitive and simpler. Under optimal conditions, this method could quantitatively detect T-2 from 0.01 to 100 μg·L^−1 with a detection limit of 0.13 μg·L^−1 and favorable recovery 91.42⁻102.49%. Moreover, the immunosensor was successfully applied to assay T-2 in feed and swine meat, which showed good correlation with the results obtained from liquid chromatography-tandem mass spectrometry (LC-MS/MS).