Rapid Colorimetric Detection Of Deltamethrin And Paraquat Based On Gold Nanoparticles

Food is the first requirement of mankind,and agriculture is the foundation of the country's people's livelihood and is the basic guarantee for the country's construction.China is the most populous country in the world,and agricultural production is particularly important.Pesticides are an indispensable part of agriculture and a tool to ensure the development of agriculture.As a large agricultural country,China has become one of the largest countries in the production and consumption of pesticides since the 1990 s.In order to meet the needs of agriculture and protect agricultural output,there are more and more types of pesticides.However,due to the irrational use of pesticides,the environmental and human hazards are increasingly highlighted.Water,crops,vegetables,fruits and other pesticides that are necessary for human daily life are always harmful to human health.For today's efficient and fast-paced life,in the face of the abruptness and diversity of problems,whether it is possible to achieve rapid,convenient and real-time detection of organic small molecules of pesticide residues is of great importance to the ecological environment and human health and safety.significance.For the pesticide small molecules,the commonly used detection methods are mainly liquid chromatography,gas chromatography,electrochemical analysis and other instrumental analysis methods and their associated technologies.However,these methods have the disadvantages of expensive equipment,cumbersome operation,and long detection time,which cannot meet the requirements of on-site detection.The noble metal nanoparticle colorimetric method has the advantages of high sensitivity,good selectivity,simple operation,rapid response,etc.,and can develop detection kits,has a certain commercial potential,and has been widely studied and applied by people.Based on gold nanoparticles,this paper developed rapid and accurate detection of deltamethrin and paraquat pesticides.The specific research content includes the following two parts:1)Rapid colorimetric detection of deltamethrin(DM)based on gold nanoparticles(Au NPs).For the most toxic detoxification insecticide deltamethrin,this section proposes a new method to detect deltamethrin using the mechanism of the core-shell structure.The surface of the functionalized nanoparticle is modified with 2-mercapto-6-nitrobenzothiazole(MNBT).The benzene ring on deltamethrin can undergo ?-? stacking interaction with the benzene ring on MNBT,thus making deltamethrin possible.Attached to the surface of Au NPs,a core-shell structure with functionalized nanoparticles as the core and deltamethrin as the shell was formed.Correspondingly,the color of the Au NPs colloid changes from burgundy to purple,and the UVvisible spectrum changes.The method has an open-eye detection limit of 0.25 ?M and a UV-visible detection limit of 5 nM.The method has good selectivity and anti-interference,and can be applied to the actual sample detection.2)Rapid colorimetric detection of paraquat(PQ)based on gold nanoparticles(Au NPs).This section proposes the use of an electrostatic force to directly and quickly determine paraquat: functionalized gold nanoparticles are surface modified with negatively charged 3-mercaptopropane sulfonate,which can be positively associated with paraquat.Electron nitrogen atoms generate an electrostatic force,which causes the agglomeration of gold nanoparticles.Accordingly,the color of Au NPs colloid changes from burgundy to blue-gray,and the UV-visible spectrum changes accordingly.The open-eye detection limit of the detection method is 0.1 mg/L,and the UV-visible detection limit is 0.001 mg/L.At the same time,it has good specific selectivity and antiinterference performance.For the actual water sample,this detection method can be well utilized.Therefore,the detection system can well meet the needs of practical testing applications.