de Marcos Susana, Callizo Esther, Mateos Elena, Galbán Javier
Analytical Biosensors Group (GBA), Analytical Chemistry Department, Faculty of Sciences, University of Zaragoza, C/Pedro Cerbuna 12, 50009 Zaragoza, Spain; Institute of Nanoscience of Aragón (INA), University of Zaragoza, Zaragoza, Spain.
Analytical Biosensors Group (GBA), Analytical Chemistry Department, Faculty of Sciences, University of Zaragoza, C/Pedro Cerbuna 12, 50009 Zaragoza, Spain.
Talanta. 2014 May;122:251-6. doi: 10.1016/j.talanta.2014.01.011. Epub 2014 Jan 31.
During the enzymatic reaction of the heme-protein Horseradish peroxidase (HRP) with hydrogen peroxide there are changes in the molecular absorption spectra of HRP and its different oxidation states which can be used for quantitative determination of the substrate. One of these intermediate oxidation states is the HRPII, with iron as an oxyferryl. This compound is assumed to be responsible for the organophosphate pesticide degradation in the Fenton reaction. In this work, the enzymatic HRP-H₂O₂ reaction has been studied, based on the effect of different pesticides on the mechanism reaction; these modifications have been used for the quantitative determination of pesticides. A mathematical model has been developed relating to the analytical signal with the pesticide concentration. Three organophosphate pesticides (diazinon, trichlorfon and tetrachlorvinphos) and one sulfamide (dichlofluanid) have been used to demonstrate the viability of the methodology and the accomplishment fulfillment of the model. Tetrachlorvinphos was chosen as the pesticide model to develop the optical sensor film for continuous pesticide determination, consisting of HRP immobilized in a polyacrylamide gel. The sensor can be used for at least 15 days and responds linearly to tetrachlorvinphos concentrations in the range from 4.0 × 10(-7) to 4.0 × 10(-6)mol L(-1). The main advantage of the methodology is its reversibility in contrast to the irreversible Fenton reaction. The HRP-H2O2 methodology has been used to measure the pesticides in a waste water sample spiked with tetrachlorvinphos.
在血红素蛋白辣根过氧化物酶（HRP）与过氧化氢的酶促反应过程中，HRP及其不同氧化态的分子吸收光谱会发生变化，这些变化可用于定量测定底物。其中一种中间氧化态是HRPII，其铁为氧合铁（IV）。该化合物被认为是芬顿反应中有机磷农药降解的原因。在这项工作中，基于不同农药对反应机制的影响，对酶促HRP-H₂O₂反应进行了研究；这些变化已被用于农药的定量测定。已建立了一个将分析信号与农药浓度相关联的数学模型。使用了三种有机磷农药（二嗪农、敌百虫和杀虫畏）和一种硫酰胺（百菌清）来证明该方法的可行性以及模型的完成情况。选择杀虫畏作为农药模型来开发用于连续测定农药的光学传感膜，该膜由固定在聚丙烯酰胺凝胶中的HRP组成。该传感器至少可使用15天，并且对浓度范围为4.0×10⁻⁷至4.0×10⁻⁶mol L⁻¹的杀虫畏呈线性响应。与不可逆的芬顿反应相比，该方法的主要优点是其可逆性。HRP-H₂O₂方法已用于测量添加了杀虫畏的废水样品中的农药。
