Research On SPR Imaging System Based On High Numerical Aperture Objective Lens

Surface plasmon resonance(SPR) detection technology become popular, because of its high sensitivity, fast detection speed,less sample consumption, biological samples without label, no damage and so on, widely used in surface detection, biochemical and immunological analysis, drug screening and environmental monitoring, it has become a measurement of metal, dielectric interface structure of high sensitivity optical technology.And most of the surface plasma detection technology just detected the point by using the prism. This paper use high numerical aperture microscope objective lens excitation of surface plasmon resonance, it is a system with multi-point detection range,combined with CCD to observe surface morphology. The surface plasmon resonance phenomenon with a high numerical aperture is not popular. In the single wavelength with the angle modulation, numerical aperture limit the range of refractive index. But in this system, designing white light as the source. The spectrometer detects the returned wavelength, detecting absorption wavelength and the refractive index, which achieve the surface morphology of samples, so as to achieve SPR imaging.This paper intends to set up the high numerical aperture objective system of surface plasmon resonance(SPR), and use a broadband source to get the SPR phenomenon and detected by spectrometer, so as to obtain the refractive index of the related data, and carries on the analysis. Specific works includes the following aspects:1. Design and built high numerical aperture of the objective lens structure SPR sensor system, as demonstrated by theory and experiment, using an objective lens excite SPR phenomenon is feasible, Moreover, objective lens are easy to get SPR imaging.2. Using this system to imaging and detecting the refractive index. This paper puts forward a new method by surface plasmon resonance imaging device to detect the refractive index, the method does not like the traditional angle modulation device, it can be real-time detect the samples by back focus plane image, which is a method avoid the mechanical errors. Extract the surface plasmon resonance data from back focus plane images, calculate the refraction index of the sample.3. Design a system control the CCD, stage and the spectrometer. Using LabVIEW control a variety of optical detection element, mechanical motion stage. At the same time, the data are collecting and storing in the computer, using image processing, scan and get refractive index curve and the sample image.4. The broadband light source through the slit, so that the incident angle is fit to achieve the right angle to SPR. This method combines the advantages of angle modulation and wavelength modulation, measurement accuracy and wide range at the same time and obtained better results.