Probes for Nanoscopy: Photoswitchable Fluorophores

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.Fil: Aramendia, Pedro Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Bionanociencias "Elizabeth Jares Erijman"; ArgentinaFil: Bossi, Mariano Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentin

Photochemical tools to study dynamic biological processes

Light-responsive biologically active compounds offer the possibility to study the dynamics of biological processes. Phototriggers and photoswitches have been designed, providing the capability to rapidly cause the initiation of wide range of dynamic biological phenomena. We will discuss, in this article, recent developments in the field of light-triggered chemical tools, specially how two-photon excitation, “caged” fluorophores, and the photoregulation of protein activities in combination with time-resolved x-ray techniques should break new grounds in the understanding of dynamic biological processes