Development of near-field optical microscopy for hydrogen ion concentration and membrane potential using environmental sensitivity dye

本研究利用飞秒脉冲激光激发双光子吸收激发双波长pH敏感染料。此外，使用扫描近场光学显微镜的收集模式探针从荧光点直接收集来自染料的荧光。用此方法，从染料溶液的荧光强度比得到了pH校准曲线，并观察到加入酸后pH的时间变化，时间分辨率为0.1s。此外，成功地观察到在三个不同的线粒体密度的pH值的变化的基础上的线粒体活性。

In this study, a dual-wavelength pH-sensitive dye was excited by two-photon absorption initiated using afemtosecond pulse laser. In addition, fluorescence from the dye was directly collected from the fluorescent point using the collection-mode probe of a scanning near-field optical microscope. By thisproposed method, a pH calibration curve was obtained from the fluorescent intensity ratio of the dyesolution, and temporal pH variations with 0.1 s time resolution following the addition of acid wereobserved. Moreover, mitochondrial activity on the basis of the pH changes was successfully observed in three different mitochondrial densities.