Abstract

In recent high-resolution fluorescence microscopies, the key to breaking the diffraction limit relies on the reaction of the fluorescent probe. STED and SAX microscopy utilize the nonlinear fluorescence emission of the probe against excitation rate caused by saturation effect [1, 2]. Localization microscopy uses a photo-switchable fluorescent dye [3]. Here, we propose a fluorescent probe providing nonlinear fluorescence response through intramolecular electron transfer, which can be used to achieve high spatial resolution using typical confocal microscopy. The nonlinear fluorescence response by the probe gives fluorescence emission from a region smaller than the diffraction-limited light focus, thereby improving the spatial resolution.

© 2014 Japan Society of Applied Physics, Optical Society of America