title: Multiphoton switching dynamics of single green fluorescent proteins.
abstract: Multi-photon driven photo-switching between dark and bright (fluorescent) states of a green fluorescent protein (GFP) mutant is demonstrated. A single-protein investigation shows the existence of two distinct bright states that display sharp two-photon cross-section bands peaked at 780 nm and at 870 nm. Fluorescence of these two species can be independently switched on and off. These results highlight a new photoconversion pathway for photochromic GFPs and can have significant applications in multi-photon confocal microscopy and in optical data-storage architectures.
authors.affiliation: INFM and Department of Physics, University of Milano Bicocca, Piazza della Scienza 3, 20126 Milano, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Chirico
authors.forename: F
authors.initials: F
authors.lastname: Cannone
authors.forename: A
authors.initials: A
authors.lastname: Diaspro
authors.forename: S
authors.initials: S
authors.lastname: Bologna
authors.forename: V
authors.initials: V
authors.lastname: Pellegrini
authors.forename: R
authors.initials: R
authors.lastname: Nifosì
authors.forename: F
authors.initials: F
authors.lastname: Beltram
mesh_terms: D049452:Green Fluorescent Proteins / Q000032:analysis* / Q000737:chemistry* / Q000235:genetics / Q000528:radiation effects; D018613:Microscopy, Confocal / Q000379:methods*; D036641:Microscopy, Fluorescence, Multiphoton / Q000379:methods*; D016297:Mutagenesis, Site-Directed; D011994:Recombinant Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics / Q000528:radiation effects; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D011994:Recombinant Proteins; D049452:Green Fluorescent Proteins