title: Photothermal microscopy: imaging of energy dissipation from photosynthetic complexes.
abstract: An idea of a photothermal imaging microscopy (PTIM) is proposed, along with its realization based on a dependence of fluorescence anisotropy of dye molecules on heat emission in their nearest vicinity. Erythrosine B was selected as a fluorophore convenient to report thermal deactivation of the excited pigment-protein complex isolated from the photosynthetic apparatus of plants (LHCII), owing to the relatively large spectral gap between the fluorescence emission bands of chlorophyll a and a probe. Comparison of the simultaneously recorded images based on fluorescence lifetime of LHCII and fluorescence anisotropy of erythrosine shows a high rate of thermal energy dissipation from the aggregated forms of the complex and, possibly, thermal energy transmission along the protein supramolecular structures. Relatively high resolution of this novel microscopic technique, comparable to the fluorescence lifetime microscopy, enables its application in a nanoscale imaging and in nanothermography.
authors.affiliation: Department of Biophysics, Institute of Physics, Maria Curie-Skłodowska University , 20-031 Lublin, Poland.
authors.forename: Wieslaw I
authors.initials: WI
authors.lastname: Gruszecki
authors.affiliation: Department of Biophysics, Institute of Physics, Maria Curie-Skłodowska University , 20-031 Lublin, Poland.
authors.forename: Rafal
authors.initials: R
authors.lastname: Luchowski
authors.affiliation: Department of Biophysics, Institute of Physics, Maria Curie-Skłodowska University , 20-031 Lublin, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Zubik
authors.affiliation: Department of Biophysics, Institute of Physics, Maria Curie-Skłodowska University , 20-031 Lublin, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Grudzinski
mesh_terms: D004923:Erythrosine / Q000737:chemistry; D005453:Fluorescence; D005454:Fluorescence Polarization; D008856:Microscopy, Fluorescence / Q000379:methods*; D055668:Photochemical Processes; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry / Q000378:metabolism*; D013696:Temperature
chemical_list: D045322:Photosynthetic Reaction Center Complex Proteins; D004923:Erythrosine