Department of Industrial Engineering, University of Salerno, 84084 Fisciano, SA, Italy.
Institute of Crystallography of the National Research Council (CNR), Department of Chemistry and Material Technology, 00015 Montelibretti, RA, Italy.
Biosensors (Basel). 2022 Apr 13;12(4):240. doi: 10.3390/bios12040240.
This work focused on the development and optimization of an impedimetric label-free immunosensor for detecting deoxynivalenol (DON). A monoclonal antibody for DON detection was immobilized on a modified gold electrode with a cysteamine layer and polyamidoamine (PAMAM) dendrimers. Cyclic voltammetry and electrochemical impedance spectroscopy techniques were used to monitor the layer-by-layer development of the immunosensor design, while electrochemical impedance spectroscopy and differential pulse voltammetry were employed to investigate the antigen/antibody interaction. The PAMAM dendrimers, allowing to immobilize a large number of monoclonal antibodies, permitted reaching, through the DPV technique, a high sensitivity and a low limit of detection equal to 1 ppb. The evaluation of the possible reuse of the immunosensors highlighted a decrease in the analytical performances of the regenerated immunosensors. After evaluating the matrix effect, the developed immunosensor was used to quantify DON in pasta samples spiked with a known mycotoxin concentration. Taking into consideration the DON extraction procedure used for the pasta samples and the matrix effect related to the sample, the proposed immunosensor showed a limit of detection of 50 ppb, which is lower than the maximum residual limit imposed by European Regulation for DON in dry pasta (750 ppb).
本工作致力于开发和优化一种用于检测脱氧雪腐镰刀菌烯醇（DON）的无标记阻抗免疫传感器。将用于 DON 检测的单克隆抗体通过半胱胺层和聚酰胺-胺（PAMAM）树状大分子固定在修饰的金电极上。循环伏安法和电化学阻抗谱技术用于监测免疫传感器设计的逐层发展，而电化学阻抗谱和差分脉冲伏安法用于研究抗原/抗体相互作用。PAMAM 树状大分子允许固定大量的单克隆抗体，通过 DPV 技术达到了高灵敏度和低检测限，低检测限可达 1 ppb。对免疫传感器可能的重复使用进行评估时，发现再生免疫传感器的分析性能有所下降。在评估基质效应后，将开发的免疫传感器用于定量经已知真菌毒素浓度污染的面食样品中的 DON。考虑到用于面食样品的 DON 提取程序和与样品相关的基质效应，所提出的免疫传感器的检测限为 50 ppb，低于欧盟法规对干面食中 DON 的最大残留限量（750 ppb）。
