Study On The Detection Technology Of Reagents For Mycotoxins

The current food safety problem is becoming more and more serious, and many issues with food are commonly caused by mycotoxins. Hence, higher requirements for limit of detection (LOD) and detection technology of mycotoxins are put forward due to its features such as high detected proportion, uneven distribution of the sample and low existing content. The present biological detection process of mycotoxins is relatively complex, high cost and difficult to operate, making it inefficient and time consuming. Therefore, a kind of rapid detection technology is needed to improve the sensitivity of detection methods, enhance the anti-interference capability and increase the detection speed. Likewise, more sensitive and portable detection equipment is also required to facilitate the detection of mycotoxins.In order to improve the detection efficiency and speed, a new detection method for determining the concentration of reagent solution directly from the color of the solution was proposed, and a rapid detection system based on dynamic white balance using double color sensors was designed as well. The main work and conclusions are as follows:(1) By studying the interaction result of Aflatoxin B11(AFB1) and nanogold particle solution, we found that the reaction solution will present different colors when AFB1 with different concentrations interact with nanogold, indicating that the color of the reaction solution will vary with the concentration of AFB1 added to it. We thereby drew a conclusion that varied colors of reaction solution can reflect the different concentrations of the detected reagent solution, and a certain color value(e.g. RGB value) is a fair indicator of the quantity of a corresponding concentration. Basing on this observation, a detection method for determining the concentration of a reagent solution by directly measuring the color of the reaction solution was presented, in which the linear relationship between the concentration and the corresponding RGB values of the color was established through experimental analysis and a fitting formula was constructed accordingly. Thus, the concentration of a detected reagent solution can be calculated with the formula once the RGB values of the reaction solution color are obtained.(2) A double-sensor-based color detection system was designed by improving the traditional single-sensor-based color acquisition system. In this detection system, two color sensors were applied to acquire the color information of the detected solution, one was employed to gather the color information of the reaction solution and the other was utilized to acquire the white balance parameters of the ambient light in real time that are used to correct the RGB values in the calculation, so as to achieve the dynamic white balance through the process of color information gathering, reduce the impact of the changes of the ambient light on the calculated RGB values of the current detected solution, and improve the adaptation of the detection system to environment, the stability of the detection process as well as the accuracy of detection results.(3) The collected data were filtered, and the data processing was optimized. In the process of color information acquisition, the output of the color sensor is a pulse signal. But in actual detection, there usually exists a kind of interference pulse with short duration and large peak. Hence, an anti-pulse interference mean filter was applied to filter out the disturbing signals and to eliminate the pulse interference. Moreover, since the filtering algorithm has some deficiencies; for instance, the filtering process is time-intensive for with every collection of data all data will be sorted, so we improved and optimized it in our practical application, leading to a significant improvement of the efficiency with ensuring the accuracy of data process.(4) The RGB color sensor TCS230D was chosen as the core component of the detection system. The working principle of it was analyzed, and the calculation relation of the output values of frequency and the corresponding RGB values was derived consequently, which will be used in establishing the linear relationship between the concentration and the corresponding RGB values of the detected solutions.(5) Several core modules of the detection system, including light source module, signal processing and conversion module, power module, filter module and LCD module, were developed, and then an experimental detection device was built. Each module was also programmed, by which the target functions namely sample frequency acquisition, data processing and LCD were realized respectively. The circuit module of the detection system was subsequently designed, achieving the functions like signal transmission and anti-interference in signal transmission process.Experimental results demonstrated the feasibility and effectiveness of this detection method by comparing with the traditional one, not only meeting the laboratory requirements of precision and accuracy but being rapid, convenient, and able to reduce the detection cost. And that this method is also available for detecting other type of relevant reagents.