Design And Realization Of Pesticide Residue Detection Instrument Based On Enzyme Inhibition Principle

In recent years,the rapid development of agricultural technology to solve the basic human food and clothing problems,improve people's material quality of life.However,the use of pesticides in modern agriculture is inevitable.Some of pesticides are highly toxic pesticides.The residues of these pesticides in agricultural products will cause great harm to human health and economic development.In these pesticides,there are two types of pesticide used widely,one is organic phosphorus,the other is carbamate.Due to the diversity of pesticides and the complexity of the detection process,the current detection of pesticide residues usually uses laboratory equipments which is very large.Although the high accuracy of these instruments,but the inherent shortcomings determine its difficult to apply to the field of rapid detection.The development of fast and portable testing equipment is very necessary to promote the supervision of pesticide residues.It is necessary to design a detection instrument from the perspective of rapid and portable.The instrument combines the principle of enzyme inhibition and Beer-Lambert Law to achieve rapid detection of organophosphorus and carbamate insecticides and a small,fast,portable device designed with embedded technology(S3C6410 core board).The contents of the article include:detection principle,hardware design and development,software design and instrument experiment.The contents divided into four parts.First of all,the paper introduces the principle and method of the instrument:the principle of enzyme inhibition and the principle of spectral absorption and related technology.The theoretical basis of the instrument design.Secondly,the pesticide residue detection system was designed based on the principle of organophosphorus and carbamate insecticides and Beer-Lambert law.The detection system first uses these two insecticides to inhibit the enzyme concentration caused by the difference in solution concentration,and through the principle of spectral absorption of this difference reflected in the optical signal;and then the optical signal switch into a current signal,through the amplification filter conversion Into the voltage signal and input to the embedded ADC(analog-to-digital converter)for processing;Finally,the display interface to display,complete the output of information and human-computer interaction.The chemical reagents required for this detection process include BTCI(thiochromoiodoiodide)as a substrate,DTNB(dithiobisitrobenzoic acid)and acetylcholinesterase as the chromogenic agent;for the optical elements,choose LED405E light-emitting diodes of the United States Thorlabs company as the light source,the collection use FGAP71 gallium phosphide PIN-type photodiode of the United States Thorlabs company which is compatible with LED405E;The filter amplifier circuit section uses the structure of the amplifier circuit to filter the high frequency interference signal consists of two parts;embedded part of the Samsung The company's S3C6410 as a core processor to build embedded platform.Finally,the instrument is analyzed and tested with the experiment,including the determination of the power of the light source,the test of the instrument performance and the field experiment.