title: Short-range spectroscopic ruler based on a single-molecule optical switch.
abstract: We demonstrate a novel all-optical switch consisting of two molecules: a primary fluorophore (Cy5) that can be switched between a fluorescent and a dark state by light of different wavelengths, and a secondary chromophore (Cy3) that facilitates switching. The interaction between the two molecules exhibits a distance dependence much steeper than that of conventional Fo rster resonance energy transfer. This enables the switch to act as a ruler with the capability to probe distances difficult to access by other spectroscopic methods, thus presenting a new tool for the study of biomolecules at the single-molecule level.
authors.affiliation: Division of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Bates
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Blosser
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Zhuang
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry; D001710:Biotin / Q000031:analogs & derivatives* / Q000737:chemistry; D002232:Carbocyanines / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D004249:DNA Damage; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D008958:Models, Molecular; D055095:Optics and Photonics; D016337:RNA, Catalytic / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D002232:Carbocyanines; D016337:RNA, Catalytic; C066114:biotin-streptavidin complex; C089187:cyanine dye 3; C085321:cyanine dye 5; D012710:Serum Albumin, Bovine; D001710:Biotin; D004247:DNA