Ramón-Azcón Javier, Valera Enrique, Rodríguez Angel, Barranco Alejandro, Alfaro Begoña, Sanchez-Baeza Francisco, Marco M-Pilar
Applied Molecular Receptors Group (AMRg(1)), CSIC, CIBER of Bioengineering, Biomaterials and Nanomedicine, Jordi Girona 18-26, 08034 Barcelona, Spain.
Biosens Bioelectron. 2008 Apr 15;23(9):1367-73. doi: 10.1016/j.bios.2007.12.010. Epub 2007 Dec 23.
A novel impedimetric immunosensor for atrazine detection has been developed. The immunosensor is based on an array of interdigitated micro-electrodes (IDmicroE) and immunoreagents specifically developed to detect this pesticide. Immunochemical determination of atrazine is possible without the use of any label. An atrazine-haptenized protein was covalently immobilized on the surface of the interdigitated mu-electrodes area (interdigits space) previously activated with (3-glycidoxypropyl)trimethoxysilane. Before, the gold electrodes were blocked using N-acetylcysteamine to prevent non-specific adsorptions. All biofunctionalization steps were characterized by chemical affinity methods and impedance spectroscopy. Immunosensors measures are made by exposing the sensor to solutions containing a mixture of the analyte and the specific antibody. With this configuration, the immunosensor detects atrazine with a limit of detection of 0.04 microg L(-1) without the use of any label. The potential of the immunosensor to analyze pesticide residues in complex sample matrices, such as red wine, has been evaluated. The results shown that after solid-phase extraction atrazine can be determined in this type of sample with a limit of detection of 0.19 microg L(-1), far below the Maximum Residue Level (MRL) established by EC for residues of this herbicide in wine.
一种用于检测阿特拉津的新型阻抗免疫传感器已被开发出来。该免疫传感器基于叉指式微电极（IDmicroE）阵列以及专门为检测这种农药而研发的免疫试剂。无需使用任何标记物即可对阿特拉津进行免疫化学测定。将阿特拉津半抗原化的蛋白质共价固定在先前用（3 - 缩水甘油氧基丙基）三甲氧基硅烷活化的叉指式微电极区域（指叉间隙）表面。在此之前，使用N - 乙酰半胱氨酸对金电极进行封闭以防止非特异性吸附。所有生物功能化步骤均通过化学亲和方法和阻抗谱进行表征。免疫传感器的测量是通过将传感器暴露于含有分析物和特异性抗体混合物的溶液中来进行的。采用这种配置，该免疫传感器在不使用任何标记物的情况下检测阿特拉津的检测限为0.04 μg L⁻¹。已经评估了该免疫传感器分析复杂样品基质（如红酒）中农药残留的潜力。结果表明，经过固相萃取后，在这类样品中可以测定阿特拉津，检测限为0.19 μg L⁻¹，远低于欧盟为葡萄酒中这种除草剂残留规定的最大残留限量（MRL）。
