The Research And Impelementation Of Food Safety Tester Based On Colloidal Gold Test

With the development of science and technology, chemical fertilizers, hormones and other synthetic substances are widely used to improve crop yields and shorten the growth cycle of carnivorous birds. It triggered a series of food pollution problems and various news events caused by food pollution has aroused widespread concern in the society. Complex operation, long detection cycle, high detection cost and uselessness in quantitative analysis are the weakness of food safety detection means today.We urgently need a food safety detection product that can realize quantitative analysis and has the advantages of simple operation, low price,etc.In this paper,a portable instrument was developed base on the Lambert Bill law of light absorption to realize the quantitative analysis of the colloidal gold strip. This instrument use CMOS image sensor to capture the gray distribution of the strip. A specific algorithm is introduced to process the grayscale data and measure the content of the harmful substance in food. In order to achieve the above-mentioned function, this paper has done the following research work:(1)This paper discussed the detection principle of the colloidal gold strip and verified the feasibility of quantitative analysis of the colloidal gold strip with Longbow Bill’s law.(2) The optical system of the photoelectric detector was designed to make the detection of colloidal gold test strip.The instrument use green LED as light source and use the CMOS sensor to tanrslate the reflected light into electrical signals to achieve data acquisition and procession.(3) The designation of the hardware circuit was completed. STM32 MCU is used for system control and data processing. FIFO chip was used as data cache to solve the problem that to directly capture the image data through I/O port is difficult.(4) Using polynomial fitting and smoothing algorithm to achieve the extraction of strip characteristics, noise signal filtering and curve fitting.the accuracy of the detection system has been improved.(5)Made the designation of data query,data analysis and data processing program,which provide convenience for application.(6)Quantitative analysis of 9 groups sample of melamine solution was made to determine the function relation between the T line feature value and the sample concentration.The system working curve was mapped through this experiment.