An ultrasensitive amperometric immunosensor for zearalenones based on oriented antibody immobilization on a glassy carbon electrode modified with MWCNTs and AuPt nanoparticles
1.SIBS-UGENT-SJTU Joint Laboratory of Mycotoxin Research, Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences,Chinese Academy of Sciences,Shanghai,People’s Republic of China;2.Institute for Agri-food Standards and Testing technology,Shanghai Academy of Agriculture Science,Shanghai,People’s Republic of China;3.College of Plant Science and Technology,Huazhong Agricultural University,Wuhan,People’s Republic of China;4.Academy of State Administration of Grain,Beijing,People’s Republic of China
Abstract:
The family of zearalenones (ZENs) represents a major group of mycotoxins with estrogenic activity. They are produced by Fusarium fungi and cause adverse effects on human health and animal production. The authors describe here a label-free amperometric immunosensor for the direct determination of ZENs. A glassy carbon electrode (GCE) was first modified with polyethyleneimine-functionalized multi-walled carbon nanotubes. Next, gold and platinum nanoparticles (AuPt-NPs) were electro-deposited. This process strongly increased the surface area for capturing a large amount of antibodies and enhanced the electrochemical performance. In a final step, monoclonal antibody against zearalenone was orientedly immobilized on the electrode, this followed by surface blocking with BSA. The resulting biosensor was applied to the voltammetry determination of ZENs, best at a working voltage of 0.18 V (vs SCE). Under optimized conditions, the method displays a wide linear range that extends from 0.005 to 50 ng mL?1, with a limit of detection of 1.5 pg mL?1 (at an S/N ratio of 3). The assay is highly reproducible and selective, and therefore provides a sensitive and convenient tool for determination of such mycotoxins.
Graphical abstract An amperometric immunosensor for the direct determination of ZENs has been developed by immobilizing anti-ZEN monoclonal antibody on multi-walled carbon nanotubest hat were deposited, along with gold and platinum nanoparticles, on a glassy carbon electrode modified with Staphylococcus protein A.
