制冷双CCD采集系统在SPR成像中的应用  

Cooled 2-CCD acquisition system applied in SPR imaging

作　　者：张玮[1] 邓焱[1] 王大千[1] 丁丽丽[1] 余兴龙[1] 

机构地区：[1]清华大学精密仪器及机械学系精密测试技术及仪器国家重点实验室,北京100084

出　　处：《仪器仪表学报》2011年第8期1751-1756,共6页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(30727001)资助项目

摘　　要：SPR双分差动干涉成像检测法既可实现高通量,又可提高折射率分辨率,能满足蛋白质组学和药物发现与开发的迫切需要。然而,如何高灵敏度获取干涉图像信号却是面临的技术难题。展示了一种制冷双CCD同时曝光采集系统,可同时采集2帧相位差为180°的干涉图像,解算后得到反映传感表面上发生生物分子相互作用时引起的折射率变化分布,经解析得到生物分子的特征参数。制冷CCD使暗电流噪声显著减小,有效提高检测分辨率;利用FPGA产生CCD控制信号,保证双CCD同时曝光,避免分时采集中光源光强波动引起的误差。以盐水为试剂,对系统的分辨率进行了检测,实验结果表明,该采集系统具有低噪声,无相移误差及效率高等优点,使SPR检测系统的分辨率达到2×10-6 RIU,满足了要求。Double-difference SPR interferometric imaging method with the advantages of high-throughput and high- resolution is potentially to be applied in proteomics and drug discovery. However, acquiring high quality interferometric images is still a challenging task. This paper presents a cooled 2-CCD acquisition system with simultaneous exposure, which can acquire two imterferometric images of the sensor surface with 180° phase difference simultane- ously. Then the refractive index changes on the sensor surface can be calculated, and the biomolecular interaction state and information can be extracted. Cooled CCDs can decrease dark current noise and improve resolution. FPGA chip is used to generate the signals to control the CCDs and makes sure that two CCDs can be exposed at the same time, which avoids the intensity fluctuation of LD laser. The resolution was tested in salt-water experiments and the results show that 2 ×10-6 refractive index resolution （unit： RIU） in SPR imaging can be achieved using this low- noise, efficient CCD acquisition system.

关 键 词：表面等离子体共振 制冷CCD 图像采集 分子相互作用 

分 类 号：TH7[机械工程—仪器科学与技术]