芯片毛细管电泳荧光检测器灵敏度的研究

The Comparison of Three Detectors in the Microchip-based Capillary Electrophoresis System with Fluorescence Detection

本文采用倒置荧光显微镜,以汞灯为激发光源,自行设计组装了芯片毛细管电泳荧光检测系统。以荧光素异硫氰酸酯(FITC)为检测对象,对双通道门控光子计数器、CH151型光子计数探测器、电荷耦合器件(CCD)三种荧光检测器的灵敏度进行了比较研究。根据芯片毛细管电泳图谱分析,FITC在双通道门控光子计数器、CH151型光子计数探测器、CCD三种检测器中的检出限(S/N=3)分别为7.0×10-10mol/L,1.2×10-9mol/L,3.2×10-8mol/L。进一步采用CH151型光子计数探测器和CCD两种较常用检测器,对FITC和荧光素、曙红和荧光素两组荧光试剂的分离及检测进行了研究。结果表明,使用CH151型光子计数探测器作为检测器,灵敏度高,基线稳定,信噪比高。

Using a home-made fluorescent detection system for microchip electrophoresis with Hg-lamp as the excitation source, the sensitivity of three detectors including two channel gated photon counter, CH151 photon counter detector and CCD was compared, and the detection limit （S/N=3） of FITC were 7.0×10^-10 mol/L ,1.2×10^-9 mol/L and 3.2×10^-8 mol/L, respectively. The two channel gated photon counter had the highest sensitivity,but so expensive that its wide application was limited at present. The sensitivity of CH151 photon counter detector was acceptable and cheap, thus it was easy to be popularized. The CCD had the lowest sensitivity and could not meet the need. The separation and detection of two groups of fluorescent reagent, FITC and fluorescein as well as fluorescein and eosin were further compared using CH151 photon counter detector and CCD, respectively. The results indicated that CH151 photon counter detector showed better selectivity and stable baseline.