基于酶抑制原理的农药残留检测仪器的设计与实现

发布时间：2018-04-05 16:11

本文选题：农药残留　切入点：快速检测　出处：《中国科学技术大学》2017年硕士论文

【摘要】：近些年来,农业技术快速发展解决了人类基本的温饱问题,提高了人们的物质生活水平。但是现代的农业生产活动中,不可避免的需要使用农药,其中不乏毒性程度较高的农药产品。这些农药在农产品中的残留会对人类健康和经济发展造成巨大的危害。在这些农药中,有两类杀虫剂农药使用最为广泛,一类是有机磷类,另一类是氨基甲酸酯类。由于农药的多样性和其检测过程的复杂性,目前对农药残留的检测多采用实验室大型仪器。大型仪器虽然精度很高但其先天的缺点决定了其难以应用于现场快速检测。快速便携的现场检测仪器的研发对于推广农药残留检测加强食品安全监督非常必要,本文便是从快速便携的角度开发设计一款检测仪器。本仪器结合了酶抑制原理和朗伯-比尔定律,实现有机磷类和氨基甲酸酯类杀虫剂的快速的检测,并通过嵌入式技术(S3C6410为核心板)设计的小型快速便携式的检测装置。文章的内容主要包括:检测原理、硬件设计与开发、软件设计与开发和仪器实验四个部分。首先,重点介绍了仪器的检测原理和方法:酶抑制原理和光谱吸收原理以及相关技术等作为本仪器设计的理论基础。其次,基于酶抑制原理和溶液的朗伯-比尔定律设计了农残检测系统。此检测系统首先利用上述两种杀虫剂对酶的抑制作用导致溶液浓度的变化,并通过光谱吸收原理将这种变化体现在光信号上;然后将光信号转换为电流信号,通过放大滤波转化成电压信号并输入到嵌入式的ADC(模数转换器)中进行处理;最后在显示界面进行显示,完成信息的输出和人机的交互。此检测过程需要的化学试剂包括作为底物的BTCI(碘化硫代胆碱)、充当显色剂的DTNB(二硫代二硝基苯甲酸)和乙酰胆碱酯酶:光学元件中,选用美国Thorlabs公司的LED405E发光二极管作为光源,后端采集使用美国Thorlabs公司的FGAP71磷化镓PIN型光电二极管;滤波放大电路部分采用前后级放大电路的结构对高频干扰信号进行滤除;嵌入式部分采用三星公司的S3C6410作为核心处理器构建嵌入式平台。最后,用实验对所设计的仪器进行分析和测试,包括光源功率的确定、仪器性能的测试以及现场实验。
[Abstract]:In recent years, the rapid development of agricultural technology has solved the basic problem of human food and clothing, and improved people's material living standard.But in the modern agricultural production, it is inevitable to use pesticides, including pesticide products with high toxicity.The residues of these pesticides in agricultural products will cause great harm to human health and economic development.Among these pesticides, two kinds of pesticides are most widely used, one is organophosphorus and the other is carbamate.Due to the diversity of pesticides and the complexity of their detection process, large laboratory instruments are used to detect pesticide residues.Although the precision of large-scale instrument is very high, it is difficult to be used in field rapid detection because of its inherent shortcomings.The research and development of fast portable field detection instrument is very necessary for popularizing pesticide residue detection and strengthening food safety supervision. This paper develops and designs a testing instrument from the point of view of rapid portability.This instrument combines enzyme inhibition principle and Lambert-Beer 's law to realize rapid detection of organophosphorus and carbamate insecticides, and a small, fast and portable detecting device is designed by embedded technology (S3C6410 as core board).The content of this paper includes four parts: detection principle, hardware design and development, software design and development and instrument experiment.Firstly, the detection principle and method of the instrument are introduced. The principle of enzyme inhibition, the principle of spectral absorption and the related techniques are used as the theoretical basis of the design of the instrument.Secondly, based on enzyme inhibition principle and Lambert-Beer 's law of solution, the detection system of agricultural residues was designed.The system firstly uses the inhibition of the above two insecticides to cause the change of the solution concentration, which is reflected in the light signal by the principle of spectral absorption, and then converts the light signal into the current signal.It is converted into voltage signal by amplifying and filtering and input into the embedded ADC (ADC) for processing. Finally, it is displayed in the display interface to complete the information output and man-machine interaction.The chemical reagents required for this detection process include BTCI (thiocholine iodide) as substrate, DTNB (dithio dinitrobenzoic acid) and acetylcholinesterase (acetylcholinesterase) as chromogenic agents: in the optical elements, the LED405E light-emitting diode of Thorlabs Company of the United States is selected as the light source.The back-end acquisition uses FGAP71 gallium phosphide PIN photodiode of American Thorlabs company, the filter amplifier circuit uses the structure of the front and rear stage amplifier circuit to filter the high-frequency interference signal.The embedded part uses Samsung S3C6410 as the core processor to build the embedded platform.Finally, the designed instrument is analyzed and tested by experiments, including the determination of light source power, the testing of instrument performance and field experiments.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP216

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