The New Technology Of On-site Application-oriented Rapid Detection Of Organophosphorus And Neonicotinoid Pesticide Residues

Since the beginning of the 21st century,food safety has become the focus of social attention.The widely used pesticides can enter the human body to endanger health directly or indirectly,so detection of pesticide residue has become a top priority.In order to more effectively protect people's health,development is convenient.Developing the fast,sensitive and efficient detection methods are especially important.As the most used pesticides in agricultural production worldwide,organophosphorus pesticides have attracted much attention,so the rapid detection of organophosphorus pesticide residues has become the focus of researchers.Among these detection methods,enzyme inhibition method as the most commonly used rapid detection method of phosphorus pesticide residues,has the advantages of simple operation and rapid reaction.this paper based the principle of color reaction of the enzyme inhibition method of cholinesterase,used the powerful data processing function and open port of the smartphone,combined with transparent reaction microchannels and optical hardware devices,take the enzyme inhibition rate as the detect index of colorimetric analysis of digital image,discussed and established relationship between the chromaticity value and the enzyme inhibition rate is discussed,realized the rapid and accurate detection of organophosphorus pesticide residues.Recently years,neonicotinoid insecticides represented by acetamiprid and thiamethoxam have rapidly developed and rapidly developed due to their low toxicity and high efficiency.Due to its unique mechanism of action on acetylcholine receptors,the detection methods for neonicotinoid pesticide residues have been mainly detected by traditional large instruments.Therefore,this paper based on the immunoassay method of fluorescence resonance transfer?FRET?,combine single-layer molybdenum disulfide?MoS₂?nanosheets and DNA-FAM fluorescent probe layers,studied and implemented to achieve rapid selective quantitative detection of acetamiprid.The main content of this paper:1.A rapid detection system of organophosphorus pesticide residues based on enzyme inhibition rate and colorimetric analysis of smartphones was established.This paper developed a smartphone detection app of organophosphorus pesticide,and designed and prepared transparent reaction microchannels and optical hardware devices.The smartphone app was developed in a highly open Android environment,verified by analyzing the color of the strips of different yellow intensities.The reaction microchannel were combined transparent polycarbonate?PC?sheet as the basement and polydimethysiloxane?PDMS?,designed by Coredraw software for carrying the detection solution.The optical hardware device was designed by 3D Studio Max,used black nylon material to prepare each component through 3D printing technology,and the light source,chip socket and light source conversion circuit are assembled together to provide a uniform illumination environment for the detection system.2.The image of the detection channel the organophosphorus pesticide residue detection by the smart phone detection system was readed and analyzed to establishes a linear relationship between the chromaticity value Y value and the inhibition rate of acetylcholinesterase,and the blank control,the standard solution,the blank sample and the sample to be tested in the channel.The enzyme inhibition rate of the sample is analyzed by he chromaticity value,which is directly used as a detection index of the pesticide residue to the mobile phone interface,and the rapid and accurate detection of the organic phosphorus pesticide residue is realized.3.The quantitative detection method of acetamiprid based on FAM-labeled aptamer chain and MoS₂ was studied.As a kind of pesticide,which has developed rapidly in recent years,acetamiprid has been mainly always detected by traditional chromatography due to its unique mechanism of action on receptors of acetylcholine neurotransmitters.Based on the immunoassay based on fluorescence resonance transfer,combined with the high fluorescence quenching ability of single layer MoS₂ nanosheets and DNA-FAM,and further optimized the experimental conditions,the detection limit of our detection method can reach 45 nM,fully meet the national requirements.