根据荧光物质的动态猝灭作用原理, 将碘化钠饱和水溶液与碱性荧光素水溶液按照特定的比例混合, 利用时间分辨设备测量猝灭后的荧光素荧光寿命。实验观察到随着碘化钠饱和溶液浓度的增加, 测量得到的荧光寿命逐步从4 ns减小至24 ps左右。如将猝灭荧光素作为仪器响应函数的标准样品, 与通常作为标准样品的二氧化硅纳米颗粒悬浮液进行对比, 实验结果显示两者非常吻合, 表明猝灭荧光素可以作为荧光衰减测试中的标准样品, 进一步研究发现这种新的标准样品一方面避免了传统测量手段中需要在不同探测波长反复测量仪器时间响应函数的问题, 更有效地减小了实验中颜色效应造成的实验误差。有望在时间分辨荧光光谱和荧光寿命成像等研究中得到应用。

Measuring the instrument response function (IRF) and fitting by reconvolution algorithms are routines to improve time resolution in fluorescence lifetime measurements. Iodide ions were successfully used to quench the fluorescence of fluorescein in this study. By systematically adding saturated NaI water solution in basic fluorescein solution, the lifetimes of fluorescein were reduced from 4 ns to 24 ps. The quenched lifetime of fluorescein obtained from the analysis of Time-Correlated Single Photon Counting (TCSPC) measurement agrees well with that from femtosecond frequency up-conversion measurement. In time resolved excitation spectra measurements, the IRF should be measured at various detection wavelengths providing scattring materials are used. This study could not only reduce the complexity of IRF measurement, but also avoid the existing color effect in system. This study should have wide applications in time resolved fluorescence spectroscopy and fluorescence lifetime imaging.