title: Origin of the anomalous two-photon absorption in fluorescent protein DsRed.
abstract: The red fluorescent protein DsRed displays a two-photon excitation band around 760 nm which is not accompanied by any feature in the corresponding one-photon spectral region (380 nm). By means of time-dependent density functional theory, we are able to explain such an effect, as arising from an electronic excitation of the DsRed chromophore with ability to couple with a charge-transfer state, through an effective two-photon absorption channel.
authors.affiliation: NEST-CNR INFM and Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy. r.nifosi@sns.it
authors.forename: Riccardo
authors.initials: R
authors.lastname: Nifosì
authors.forename: Yi
authors.initials: Y
authors.lastname: Luo
mesh_terms: D015502:Absorptiometry, Photon; D000465:Algorithms; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005453:Fluorescence; D008164:Luminescent Proteins / Q000737:chemistry*; D008958:Models, Molecular
chemical_list: D008164:Luminescent Proteins; C413663:fluorescent protein 583