Construction And Experimental Study Of An Angle Scanning Based Optical Surface Plasmon Resonance Biosensor Using A Laser Line Generator

As the development of SPR (Surface Plasmon Resonance) technology andwidely being used in food safety, toxic molecules detection, the environmental protection,and agriculture, biological analyzer based on this technology has intensely gained to bedeveloped and applied. In order to meet the requirements of high sensitivity, real-time andfast detection and low-cost, the portable and low cost SPR biological analyzer has openeda new development direction. An angle-scanning SPR biosensor using a laser linegenerator was designed to meet the requirements for portable bioanalyzers, which hasovercome the drawbacks of hard alignment and fine adjusting angle compared to the SPRbiosensor which was developed in our group using one laser line generator. Themeasurement precision was greatly improved and the angle detection was obtainedefficiently. With regarding to the data collection, the formal SPR biosensor whichemployed linear array CCD to implement the data acquisition and processing can onlyobtain one dimensional data and one sample was detected at the same time. With theprogress of the industrial camera and area array CCD technology, the two dimensionalresults achieved from the muti-sample were obtained simultaneously by using SV1410FMdigital camera (area array CCD, DAHENG IMAGE). Due to this reason, study of theangle-scanning optical surface plasmon resonance biosensor which based on a laser linegenerator and area array CCD has significantly developed prospects.This thesis presents a novel design method of an angle-scanning optical surfaceplasmon resonance biosensor in which the laser line generator was used as a light source ofthe biosensor. Correspondingly, the mechanism of the SPR biosensor was constructed andthe working principle was also introduced in this thesis. A variable speed DC motor wasused to realize the speed regulator to drive the laser line generator to move back and forth.A low offset regulated power supply based on TPS74104integrated chip was used tosupply the laser line generator to get uniform laser beam and to obtain better image and data. The rectangular prism was employed instead of the triangular prism to reduce theinfluence of the reflected light to obtain the high resolution.Regarding to improving the data acquisition, the VC6.0Software Developmentplatform was used to implement the digital camera control to obtain the image and dataprocessing simultaneously. Compared to the previous SPR sensor using the one line lasergenerator, the data and images obtained from the industrial camera have been steadily andhomogeneously. The difficulty of data processing was greatly reduced. The ideas andalgorithms on data processing were improved before the data was analyzed. According tothe measurement results, the relationship between the motor speed of the laser linegenerator and sample collection time was validated. And the accuracy approximately is1.225o/mm. Finally, the experiments were designed to validate the performance of theoptical biosensor using different volume fraction ethanol of10%,25%,30%,40%,50%,60%, respectively and the SPR curve and resonance curve were also obtained The resultsdemonstrate that this angle scanning type optical surface plasmon resonance biosensorusing a laser line generator has better linearity and sensitivity. The correlation coefficient is0.9988and the sensitivity is845.60(resonance pixels position per volume fraction ethanol),respectively.