Fluorescence is an established technology for studying molecular processes and molecular interactions. More recently fluorescence became a leading method for detection, sensing, medical diagnostics, biotechnology, imaging, DNA analysis, and gene expression. Consequently, precise and accurate measurements in various conditions have become more critical for proper result interpretations. Previously, in Part 1, we discussed inner filter effect type I, which is a consequence of the instrumental geometrical sensitivity factor and absorption of the excitation. In this part, we analyze inner filter effect type II and discuss the practical consequences for fluorescence measurements in samples of high optical density (absorbance/scattering). We consider both the standard square and front-face experimental configurations, discuss experimental approaches to limit/mitigate the effect and discuss methods for correcting and interpreting experimental results.

荧光是研究分子过程和分子相互作用的成熟技术。最近，荧光成为检测、传感、医学诊断、生物技术、成像、DNA 分析和基因表达的主要方法。因此，在各种条件下精确和准确的测量对于正确的结果解释变得更加重要。之前，在第 1 部分中，我们讨论了 I 型内部滤波器效应，这是仪器几何灵敏度因子和激发吸收的结果。在这一部分中，我们分析了 II 型内部过滤效应，并讨论了在高光密度（吸光度/散射）样品中进行荧光测量的实际后果。我们同时考虑标准方形和正面实验配置，