Institute for Optical Materials and Technologies “Acad. J. Malinowski”, Bulgarian Academy of Sciences, “Acad. G. Bonchev” str. Bl. 109, 1113 Sofia, Bulgaria Sofia University.”St. Kliment Ohridski, Faculty of Chemistry and Farmacy, 1 James Bourchier Blvd., 1164 Sofia, Bulgaria Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, “Acad. G. Bonchev” str. Bl....

Isolated single (Xenopus) muscle fibers were stained with a non-permeant potential-probing dye, merocyanine rhodanine (WW375) or merocyanine oxazolone (NK2367). When the fiber was massively stimulated, an absorption change (wave a), which seemed to reflect the action potential, occurred. Simultaneous recording of optical changes and intracellular action potentials revealed that the time-course ...

Cells from three different human neuroblastoma cell lines and normal human bone marrow cells were exposed to the lipophilic fluorescent dye, merocyanine 540 (MC 540), and white light. In vitro clonogenic tumor cells were inactivated up to 25,000 times more rapidly than multipotent hematopoietic progenitor cells (CFU-GEMM). It is conceivable that this pronounced difference in sensitivity to MC 5...

The effects of temperature on spontaneous action potential activity in the 7-9 somite embryonic precontractile chick hearts were investigated using an optical method for monitoring membrane potential. A potential-sensitive merocyanine-rhodanine dye was used as an optical probe. Cooling caused a marked decrease in the frequency of occurrence of the spontaneous action potential. This slowing was ...

We show that FRET between Pacific Blue (PB) and Alexa488 (A488) covalently attached to a DNA scaffold can be reversibly controlled by photochromic switching of a spiropyran derivative. With the spiropyran in the closed spiro isomeric form, FRET occurs freely between PB and A488. UV-induced isomerization to the open merocyanine form shuts down the FRET process by efficient quenching of the PB ex...

The potential of E–Z photoisomerization in molecular organic light-to-thermal conversion and storage an E–styryl merocyanine system was studied a polar acidic medium. A photoswitchable styryl dye (E)-2-(2-(2-hydroxynaphthalen-1-yl)vinyl)-3,5-dimethylbenzo[d]thiazol-3-ium iodide synthesized for the first time. reversible photoisomerisation investigated using UV-Vis spectroscopy DFT calculations....

Molecular switches on metal surfaces typically show very little photoreactivity. Using scanning tunneling microscopy, we show that the ring-opening-ring-closing switch nitrospiropyran thermally and optically isomerizes to the open merocyanine form on a Bi(110) surface. Irradiation by blue light of a monolayer of spiropyran molecules leads to mixed domains of the two isomers. At large illuminati...