| Microfluidic chip technology is a system that uses microfabrication technology to construct microfluidic channels on semiconductor or polymer material chips.It transfers the experiment and analysis process to the chip structure,which can perform rapid,accurate and high-throughput analysis of samples.With the characteristics of high throughput and miniaturization,it can not only reduce the detection time and sample consumption,but also improve the detection accuracy of samples.It has been widely used in in various fields.Micro-sample detection technology is one of the most important research contents in microfluidic technology.Traditional microfluidic chip detection methods require built-in electrodes,high-voltage electric or magnetic fields,etc.,but the size of the flow channel and reaction cell of the chip is generally in the order of micrometers to millimeters,which makes it difficult to insert the macroscopic detection elements,and the microscopic components such as chromatography and optics.The small detector is still in the research stage,so it is difficult to realize the portability of the microfluidic quick detection instrument,which seriously affects the popularization and promotion of microfluidic technology.With the development of image technology,the method of using image methods to detect samples in the microfluidic chip reaction cell has become a new research method,this method does not need to modify the microchannel and will not cause secondary pollution to the sample,which can complete the detection of the sample composition by collecting the image through the camera.In this paper,the image technology was applied to the detection technology of microfluidic chip,the sample concentration detection was realized,and the practical application of nitrite nitrogen concentration detection was carried out.The main work of the paper was as follows:(1) The detection principle of the combination of microfluidic detection technology and image method was explained,the overall scheme of the detection system,the image acquisition platform was designed,and the microfluidic chip for experiment was designed and processed.(2) The OpenCV computer vision library was used to realize the image processing of the color image of the microfluidic chip.The noise interference of the image is eliminated by the median filtering method;according to the corresponding relationship between the nitrite nitrogen concentration and the chromaticity after biochemical color development,the image was converted from the RGB color space to the HSV space and the S-component image with obvious difference between target and background was obtained;by comparing the segmentation effects of different algorithms,a dynamic threshold segmentation algorithm was proposed to segment the S-component image of the chip image;the centroid extraction algorithm was designed and the feature value of the target area was analyzed,and the RGB value representing the nitrite nitrogen concentration image was obtained(3) The application research on rapid detection of nitrite nitrogen content in drinking water was carried out.The relationship between the thickness of the chip reaction cell,the diameter of the reaction cell,the temperature,the color development time of the reagent and other parameters was investigated,and a standard curve for the detection of the concentration of nitrite nitrogen was drawn.The results showed that when the chip reaction cell thickness was 4mm,the color development time was 3min,and the standard curve was between 0.4?1mg/L,the sensitivity was highest,the detection range was between 0.4?1 Omg/L,and the lowest detection concentration was 0.4mg/L;the recovery rate of standard addition wass 96.9%?104.0%;the consumption volume of the sample and the volume of the developer were only 1/10 of the spectrophotometric method,and 1/250 and 1/50 of the colorimetric method respectively;temperature had little effect on the test results.The image-based microfluidic chip detection method designed in this paper has low cost,short time,high throughput,high resolution,small error,no pollution to the solution to be tested,and can meet the needs of microfluidic rapid detection technology,which is an important and beneficial supplement to traditional flow control detection technology.Figure [34] table [16] reference [79]... |
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