| As the main pesticides used in field plant protection in my country,organophosphorus pesticides are widely used.Due to the current spraying equipment and technology,a large number of pesticide droplets are deposited in the farmland soil.Organophosphorus pesticides have strong biological toxicity.They can inhibit the binding of acetylcholine to receptors and lead to the accumulation of neurotransmitters in animals.Organophosphorus pesticides deposited in the soil accumulate in food due to bioaccumulation and endanger human health.The current methods for detecting organophosphorus pesticides,such as chromatography and spectroscopy,have problems such as complicated detection steps,the need for large-scale special instruments,the need for professional technicians,the time-consuming and labor-intensive detection,and the high cost,which greatly affects the treatment of organophosphorus pesticides.The efficiency of pesticide testing.This article is based on the advantages of easy synthesis of nucleic acid aptamers and the ability to specifically bind to the target.When the glass nanopipettes are used as the sensor matrix,they have the characteristics of nanopores and spatial geometric asymmetry,which can block ionic current and generate current rectification.A new type of nanopipette aptamer sensor detection scheme that is specific to the target and low-cost is designed.The main work content of this paper mainly includes the following three aspects:（1）Using glass nanopipettes as the matrix material of the sensor,the surface modification of the nano-conical pores of the glass tube can specifically identify the aptamer of isocarbophos,using the spatial conformation of the aptamer and isocarbophos.Changes and signal transduction phenomena when ions in the solution pass through the nanopores.A nanopipette aptamer sensor that can specifically detect isocarbophos was designed,and the aptamer Apt-1 modified with glass nanopipette was investigated.The concentration of the solution,the concentration of the aptamer Apt-2solution,the p H value of the incubation solution,and the incubation time of the aptamers Apt-1,Apt-2 and isocarbophos,optimize the detection performance of the nanopipette aptamer sensor.Under the optimal conditions,the linear detection range of the nanopipette aptamer sensor for isocarbophos is 1×10-88)7)mol·L（-1） 1×10-68)7)mol·L（-1）,and the detection limit is as low as 1.91×10-98)7)mol·L（-1）.（2）The aptamer that can specifically recognize malathion is modified on the matrix material of nanoglass tube,and the nanopipette aptamer sensor that can specifically detect malathion is designed and manufactured,and the aptamer is investigated.The concentration of Apt-1 and Apt-2 solutions,the p H value of the incubation solution,and the incubation time of the aptamer and malathion,etc.affect the detection performance of this nanopipette aptamer sensor.Under the determined optimal conditions,the linear detection range of the nanopipette aptamer sensor for malathion is 1×10-88)7)mol·L（-1） 2×10-78)7)mol·L（-1）,and the detection limit is as low as 3.33×10-98)7)mol·L（-1）.（3）Obtain surface soil samples at an outdoor site,extract the soil samples to obtain the extraction solution,and use the standard addition method to test the detection ability of the nanopipette aptamer sensor on the actual samples,that is,add isocarbophos to the extraction solution.Reagents and malathion reagents are detected using sensors.To the soil sample extract,add water carbamiphos and malathion solutions to make them a detection solution containing 1×10-88)7)mol·L（-1） carbamiphos and malathion,and perform detection.The sample contains ammonium sulfaphos and malathion.The recovery rate is 95.40%103.70%,the relative standard deviation（RSD）is3.76%6.77%,and the recovery rate of malathion in the sample is 94.30%102.90%,and the relative standard deviation（RSD）is 3.65%7.02%.This shows that the nanopipette aptamer sensors designed to detect isocarbophos and malathion respectively can complete the detection of actual samples. |
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