Opt Lett. 2022 Sep 1;47(17):4455-4458. doi: 10.1364/OL.465605.
Imaging of molecular-specific photophysical parameters such as fluorescence intensity, emission band shape, or fluorescence decay is widely used in biophysics. Here we propose a method for quantitative mapping of another molecular-specific parameter in living cells, two-photon absorption cross section, based on the fluorescence saturation effect. Using model dye solutions and cell culture, we show that the analysis of the fluorescence signal dependencies on the intensity of two-photon excitation within the range typical for routine two-photon microscopy experiments allows one to reconstruct two-photon absorption cross section maps across the sample. We believe that the absorption cross section contrast visualized by the proposed fluorescence saturation imaging microscopy could be a new tool for studying processes in living cells and tissues.
在生物物理学中，广泛应用于成像分子特异性光物理参数，如荧光强度、发射带形状或荧光衰减。在这里，我们提出了一种基于荧光饱和效应定量映射活细胞中另一个分子特异性参数——双光子吸收截面的方法。通过模型染料溶液和细胞培养，我们表明，在常规双光子显微镜实验典型的双光子激发强度范围内分析荧光信号的依赖性，可以重建整个样本的双光子吸收截面图。我们相信，通过所提出的荧光饱和成像显微镜可视化的吸收截面对比度，可以成为研究活细胞和组织中过程的新工具。
