title: Two-photon-induced Förster resonance energy transfer in a hybrid material engineered from quantum dots and bacteriorhodopsin.
abstract: Energy transfer from nanostructures to biological supramolecular photosystems is an important fundamental issue related to the possible influence of nanoobjects on biological functions. We demonstrate here two-photon-induced Förster resonance energy transfer (FRET) from fluorescent CdSe/ZnS quantum dots (QDs) to the photosensitive protein bacteriorhodopsin (bR) in a QD-bR hybrid material. The two-photon absorption cross section of QDs has been found to be about two orders of magnitude larger than that of bR. Therefore, highly selective two-photon excitation of QDs in QD-bR complexes is possible. Moreover, the efficiency of FRET from QDs to bR is sufficient to initiate bR photoconversion through two-photon excitation of QDs in the infrared spectral region. The data demonstrate that the effective spectral range in which the bR biological function is excited can be extended beyond the band where the protein itself utilizes light energy, which could open new ways to use this promising biotechnological material.
authors.forename: Victor
authors.initials: V
authors.lastname: Krivenkov
authors.forename: Pavel
authors.initials: P
authors.lastname: Samokhvalov
authors.forename: Daria
authors.initials: D
authors.lastname: Solovyeva
authors.forename: Regina
authors.initials: R
authors.lastname: Bilan
authors.forename: Alexander
authors.initials: A
authors.lastname: Chistyakov
authors.forename: Igor
authors.initials: I
authors.lastname: Nabiev
mesh_terms: D001436:Bacteriorhodopsins / Q000737:chemistry*; D019187:Cadmium Compounds / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D017785:Photons; D045663:Quantum Dots / Q000737:chemistry*; D018036:Selenium Compounds / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; D001436:Bacteriorhodopsins; C058667:cadmium selenide; C031238:zinc sulfide