超快微光分子光谱探测技术研究

按照超快极微弱分子吸收光谱学,荧光光谱学,时间分辨光谱学以及偏振荧光光谱学探测特性,设计、集成组建了能够探测紫外－可见－红外快到飞秒时间分辨的单分子光学事件的激光瞬态光谱仪.其光源有从300 nm到3000 nm连续可调的飞秒激光器、纳秒氢灯及连续氙灯.光谱分辨率达0.05 nm,在泵浦探测差异吸收下有小于150 fs的时间分辨率.谱仪能够实时给出光谱曲线及生物分子组分寿命.利用该谱仪探测了PSⅡCC,PSⅡRC的能量传递动力学.在83 K温度下PSⅡCC中的β-Car分子接收507 nm光能,以单步跃迁和随机转移的方式通过Chl a641.5637/638分子传递光能到反应中心Chl a683.2680/681,平均传能时间为77 ps,有59.94％的组分用355 ps时间电荷重组.在PSⅡRC中的β-Car分子接收507 nm光能,由Chl a641.5637/638分子传递光能通过Chl a678.2675.5到反应中心,平均传能时间为88.5 ps.在83 K温度下,反应中心复合物离子对;P680+·pheo-］平均再复合寿命为19.35 ns.

Studies on Detection Technique of Ultrafast Glimmer Molecule Spectra

According to detection characteristics of ultrafast glimmer molecule absorption spectroscopy, fluorescence spectroscopy, time-resolved spectroscopy and polarization fluorescence spectroscopy,the laser transient spectrometer has been perfectly assembled to detect the femtosecond time-resolved single molecule optics events from 300 nm to 3000 nm range. Spectrum resolution of the spectrometer is 0.05 nm, its time resolution is less than 150 fs in the pump-probe difference absorption. Energy transfer kinetics of PSII CC and PSII RC has been detected by this spectrometer. 507 nm light energy is absorbed by β-Car molecule in the PSII CC, and via Chl a641.5637.638 molecule transfer excitation energy to reaction center Chl a683.2680/681,average transfer time is 77 ps, charge recompose time is 355 ps in the components of 59.94% at 83 K. 507 nm light energy is absorbed by β-Car molecule in the PSII RC, and via Chl a641.5637/638molecule transfer to Chl a678.2675.5, average transfer time is 88.5 ps, average recombination lifetime in the reaction center radical-pair;P680+pheoa-］ is 19.35 ns at 83 K.