Abstract:This paper describes a new method, multiphoton excitation fluorescence detection combined with capillary electrophoresis separation. The excitation source was a self mode-locked femtosecond titanium-sapphire laser (Spectra-physics Inc.), producing a stream of pulses with a pulse duration of about 100 fs at 82 MHz repetition rate. Its average power was about 200 mW at 750 nm. The laser beam was focused into a thin wall flow cell of capillary electrophoresis. A high numerical aperture objective (100×NA 1.25) was chosen to focus the laser beam and to collect the fluorescence emitted by detecting molecules. Then the fluorescence was detected by a fast response PMT. All data were acquired and processed by a microcomputer. For three biological molecules, 5HT, FAD and NADH, it was demonstrated that they can be separated and detected efficiently by this method with three-photon and two-photon excitation respectively using only one 750 nm laser beam. The detection limits were 1.0×10-6 mol·L-1 for 5HT, 7.4×10-7 mol·L-1 for FAD and 9.8×10-7 mol·L-1 for NADH using the criterion of three standard deviations above background. The results are much better than those with UV absorption detection by one or two magnitudes.
孙云旭,朱 峰,马万云*. 多光子激发荧光与毛细管电泳联用的实验研究[J]. 光谱学与光谱分析, 2005, 25(04): 502-505.
SUN Yun-xu, ZHU Feng, MA Wan-yun*. Study on Multi-Photon Excited Fluorescence Combined with Capillary Electrophoresis . SPECTROSCOPY AND SPECTRAL ANALYSIS, 2005, 25(04): 502-505.
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