Skovsen Esben, Snyder John W, Ogilby Peter R
Department of Chemistry, University of Aarhus, Arhus DK-8000, Denmark.
Photochem Photobiol. 2006 Sep-Oct;82(5):1187-97. doi: 10.1562/2006-04-10-IR-868.
A microscope is described in which singlet molecular oxygen, O2(a1deltag), is produced in a femtoliter focal volume via a nonlinear two-photon photosensitized process, and the 1270 nm phosphorescence from this population of O2(a1deltag) is detected in a photon counting experiment. Although two-photon excitation of a sensitizer is less efficient than excitation by a one-photon process, nonlinear excitation has several distinct advantages with respect to the spatial resolution accessible. Pertinent aspects of this two-photon O2(a1deltag) microscope were characterized using bulk solutions of photosensitizers. These data were compared to those obtained from a single biological cell upon linear one-photon excitation of a sensitizer incorporated in the cell. On the basis of the results obtained, we outline the challenges of using nonlinear optical techniques to create O2(aldeltag) at the single cell level and to then optically detect the O2(aldeltag) thus produced in a time-resolved experiment.
本文描述了一种显微镜，其中通过非线性双光子光敏化过程在飞升级焦体积中产生单重态分子氧O₂(a¹Δg)，并在光子计数实验中检测来自该O₂(a¹Δg)群体的1270 nm磷光。尽管敏化剂的双光子激发效率低于单光子过程激发，但非线性激发在可达到的空间分辨率方面具有几个明显优势。使用敏化剂的本体溶液对这种双光子O₂(a¹Δg)显微镜的相关方面进行了表征。将这些数据与在细胞中掺入的敏化剂进行线性单光子激发时从单个生物细胞获得的数据进行了比较。根据获得的结果，我们概述了使用非线性光学技术在单细胞水平上产生O₂(a¹Δg)，然后在时间分辨实验中光学检测由此产生的O₂(a¹Δg)所面临的挑战。
