title: Optically switchable chelates: optical control and sensing of metal ions.
abstract: This study introduces new concepts in the design, synthesis, and in vitro and in vivo characterization, manipulation, and imaging of organic chelates whose association with metal ions is rapidly and reversibly controlled by using light. Di- and tricarboxylic group bearing photochromes, nitrobenzospiropyran (nitroBIPS), undergo rapid and reversible, optically driven transitions between their spiro (SP) and fluorescent merocyanine (MC) states. The MC state of nitroBIPS-8-DA binds tightly to various metal ions resulting in specific shifts in absorption and fluorescence, and the dissociation constant for its Gadolinium complex in water is measured at approximately 5 microM. The metal-bound MC state is converted to the weaker-binding SP state with use of 543 nm light, while the SP to MC transition is complete with use of 365 or 720 nm (2-photon) light within several microseconds. Fluorescence imaging of the MC state of nitroBIPS-8-TriA was used to quantify the rate and efficiency of optical switching and to provide a real-time readout of the state of the optically switchable chelate within living cells.
authors: Department of Physiology, University of Wisconsin, 1300 University Avenue, Madison, Wisconsin 53706, USA.
authors: Tomoyo
authors: T
authors: Sakata
authors: David K
authors: DK
authors: Jackson
authors: Shu
authors: S
authors: Mao
authors: Gerard
authors: G
authors: Marriott
mesh_terms: D002118:Calcium / Q000737:chemistry; D002614:Chelating Agents / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry / Q000528:radiation effects; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008027:Light; D019216:Metals, Heavy / Q000737:chemistry*; D015394:Molecular Structure; D055095:Optics and Photonics; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010777:Photochemistry; D011714:Pyrans / Q000737:chemistry*; D013141:Spiro Compounds / Q000737:chemistry*
chemical_list: D002614:Chelating Agents; D005456:Fluorescent Dyes; D028581:Lanthanoid Series Elements; D019216:Metals, Heavy; D009942:Organometallic Compounds; D011714:Pyrans; D013141:Spiro Compounds; D002118:Calcium