Potentiometric Enzyme Sensor Development And Rapid Detection Of Organophosphorus Pesticides

With the high efficiency of killing pests, the organ phosphorus pesticide is one of widely used pesticides in the agriculture. However, due to the large scale of their application, the residua of organ phosphorus pesticides had brought serious environment pollution which became a greater and greater threaten to the health of human beings at present. Conventional methods for detecting residual organ phosphorus pesticides included chromatography, mass spectrometry, spectroscopy, et al., they were time consuming and costly, and were hard to satisfy the increasing requirements of the online detection. As a comparison, biosensors provided a promising way to detect organ phosphorus pesticides which was both rapid and simple.The design theory of the organ phosphorus pesticide biosensor is based on the irreversible restrain of acetyl cholinesterase by the organ phosphorus pesticide. However, this kind of biosensor only can use only once so that its cost is very high. So, a novel repetitive organ phosphorus pesticide biosensor is developed by the restrain of alkaline phosphatase. The mostly experiments are as follows.1 The development of the graphite electrode modified HRP and the detection of H₂O₂The rapid precise detection of H₂O₂ is the important foundation of the organ phosphorus pesticide biosensor. In this experiment , the bare graphite electrode, the graphite electrode modified POPD, the graphite electrode modified Nafion are used as the base electrode respectively and the HRP is immunized on the base electrode by the method of regenerated silk fibroin embed, Poly vinly alcohol embed, chitosan embed, the nano-Au adsorption and so on. The experiment show that the detection limit of HRP/nano-Au/POPD/graphite electrode to H₂O₂ is 8.82×10^-8mol/L, the detection range is 3.53×10^-78.23×10^-4 mol/L. It can be used as the base electrode to develop the organ phosphorus pesticide biosensor. The detection limit of HRP/nano-Au/ cysteine/Nafion/graphite electrode is 8.82×10^-9mol/L, the detection range is...