Probes for Nanoscopy: Photoswitchable Fluorophores

Abstract

In recent years, new concepts have emerged for imaging in a far-field fluorescence microscope with resolution under the diffraction limit. All these concepts bear in common the use of molecular states of the probe to switch its signal between a fluorescent and a dark state. So far, in these techniques different kinds of molecular switches have been applied, whose photochemical features become a crucial fact for the success. In this chapter, we will discuss how the two isomeric forms of a photochromic system can be used to design a fluorescent switch for that purpose. We will focus on the photochemical and photophysical relevant properties for these systems to fulfill the requirements of a suitable probe for the different strategies currently used in fluorescence nanoscopy. Examples containing diverse photochromes and their application in super-resolution fluorescence imaging will be described.