INQUIMAE   12526
INSTITUTO DE QUIMICA, FISICA DE LOS MATERIALES, MEDIOAMBIENTE Y ENERGIA
Unidad Ejecutora - UE
capítulos de libros
Título:
Strategies to Switch Fluorescence with Photochromic Oxazines
Autor/es:
E. DENIZ; J. CUSIDO; M. TOMASULO; M. BATTAL; I. YILDIZI. YILDIZ; M. PETRIELLA; M. L. BOSSI; S. SORTINO; F. M. RAYMO
Libro:
Organic Synthesis and Molecular Engineering
Editorial:
John Wiley & Sons
Referencias:
Lugar: Hoboken, NJ; Año: 2014; p. 197 - 212
Resumen:
A photochromic oxazine can be assembled in a single synthetic step from commercial precursorsand condensed to fluorescent aldehydes under acidic conditions. The local excitation of thephotochromic component of the resulting fluorophore?photochrome dyads opens the oxazinering to produce a zwitterionic isomer. This structural transformation extends the conjugation ofthe fluorescent component and shifts its main absorption band bathochromically. Illumination ata wavelength positioned within this band excites exclusively the fluorescent component of thephotogenerated isomer. As a result, the emission of such fluorophore?photochrome dyads canbe switched under optical control, relying on the interplay of activating and exciting beamsdesigned to address the photochromic and fluorescent components respectively. In the case of acoumarin derivative, the photogenerated isomer is sufficiently bright to be localized at the singlemoleculelevel. Furthermore, this particular fluorophore?photochrome dyad can be encapsulatedwithin micellar assemblies of an amphiphilic co-polymer and the resulting supramolecularconstructs can be operated in aqueous environments. Indeed, the fluorescence of thesenanoparticles can be switched on and off with the photoinduced interconversion of thephotochromic component. Furthermore, the photoswitchable character of these supramolecularconstructs offers the opportunity to overcome diffraction and reconstruct fluorescence imageswith resolution at the nanometer level. Thus, our strategies for fluorescence activation withphotochromic oxazines can eventually lead to the realization of an entire family ofphotoswitchable fluorophores for the visualization of biological samples with subdiffractionresolution.