荧光发射强度影响因素及荧光猝灭实验研究

摘要

荧光发射强度在荧光显微术科学观测中至关重要.理论分析了三大影响荧光发射强度的重要因素:分子吸收激发光光子的能力、荧光量子产量及其荧光饱和与荧光猝灭,指出选择具有大光吸收截面和高量子产量的荧光分子,能有效保证荧光发射强度；确定合理的激发光强度范围,可避免不必要的荧光饱和现象.进一步实验研究了超高真空和大气环境下的荧光猝灭现象,得出超高真空时荧光分子的荧光猝灭现象极不明显,而大气环境可造成荧光光强指数递减的结论.%The fluorescence emission intensity is vital to scientific observation using fluorescence microscopy. Three important factors influencing the intensity of fluorescence emission were theoretical analyzed, including the absorption ability of excitation photons, fluorescence quantum yield, and fluorescence saturation & fluorescence quenching. The authors pointed out that fluorescence molecules with large optical absorption cross section and high quantum yield can effectively guarantee the fluorescence e-mission intensity, and one also can avoid unnecessary fluorescence saturation if excitation intensity was determined in a reasonable range. Furthermore, fluorescence quenching experiments were studied in ultra-high vacuum (UHV) and atmospheric environment, respectively. We found that fluorescence quenching in UHV was imperceptible, while the fluorescence intensity in the atmosphere decreased exponentially.