| In recent years,many basic research area such as genomics,proteomics,systems biology have been developed rapidly,and the practical application of clinical disease diagnosis,drug screening,immunology have been increased,while the challenge of vivo determination,single molecular analysis,online determination and other difficult demand have been strengthened.Driven by the above factors,high throughput optical biosensor has become a hot research field.Reflectance differential modulated biosensor is a high throughput optical biosensor,which will be studied in the following aspects:Firstly,we summarized the characteristics of optical biosensor detection system,and analyzes the development trend and the practical requirements of high throughput optical biosensor.In view of the characteristics of the reflectance differential modulated biosensor,the paper presented the design scheme of the detection system.Secondly,in this paper,the software is programmed to realize the precise control of the parameters of the light source controlling system,the camera controlling system and the data storage process,which improved the efficiency and controllability of the sensor data acquisition,and provide the hardware foundation for the experiment.We evaluated the performance of the hardware after that.Thirdly,according to the characteristics of the acquired image,we discussed the applicability of common image restoration,image segmentation and image extraction algorithm in this system.In view of the existing pulse(salt and pepper)noise and Gaussian noise,we chose the adaptive Median/Wiener filter for image restoration scheme.The effect of some commonly used edge detection operator on image edge extraction of the system image is analyzed;the basic global threshold processing and Otsu threshold segmentation method of target and background binary segmentation effect were studied,and according to the result,Otsu method was chosed as the system image segmentation foundation;In consideration of the common light inhomogeneous and low value of object / background in high throughput biological sensing,the image is divided into blocks with Otsu method enhanced by edge detection operator for image segmentation;for the binarization image after segmentation,the connected region labeling method is selected for the target extraction,as the last step of image processing of this paper.Lastly,the calibration and application of the system are carried out.We devised and improved the calibration scheme of transducer thickness,so the influence of the transducer fabrication process,environmental temperature,and the variation of the illumination conditions are avoided and the working curve near the 369 nm SiO2 film is obtained.By the immune reaction between human IgG and Rabbit anti human IgG,the change of reflectance of different concentrations of Rabbit anti human Ig G sample was tested,and the optical thickness of the film formed by different concentrations of the sample with the surface probe molecules was determined;the experimental results were tested by using the method of ellipse polarization.Experimental results show that the system can sense and process and analysis 288 samples in one time;for different concentrations of Rabbit anti human IgG samples,there is a positive correlation between the value of change of reflectance ?R and concentration D from the red and green light differential method;when the sample concentration was 10 ?g/mL to 120?g/m L,the relationship between the signal and the concentration of the sample is approximately logarithmic curve.For lower and higher concentrations,there is yet to be further studied. |
PDF Full Text Request