Jean-Claude Bunzli - Luminescent Bimetallic Lanthanide Bioprobes for Cellular Imaging with Excitation in the Visible-Light Range

Version 1

      Publication Details (including relevant citation   information):

      Deiters,E., Song,B., Chauvin,A.S., Vandevyver,C.D.B., Gumy,F.,   Bunzli,J.C.G. Chemistry-A European Journal  2009 15 (4) 885-900

      Abstract: A series of homoditopic ligands H2LCX   (X=4-6) has been designed to self-assemble with lanthanide ions   (Ln(III)), resulting in neutral bimetallic helicates of overall   composition [Ln2(L-CX)(3)] with the aim of testing the influence   of substituents on the photo-physical properties, particularly   the excitation wavelength. The complex species are   thermodynamically stable in water (log beta(23) in the range   26-28 at pH 7.4) and display a metal-ion environment with   pseudo-D-3 symmetry and devoid of coordinated water molecules.   The emission of Eu-III, Tb-III, and Yb-III is sensitised to   various extents, depending on the properties of the ligand donor   levels. The best helicate is [EU2(L-C5)(3)] with excitation   maxima at 350 and 365 nm and a quantum yield of 9%. The viability   of cervix cancer HeLa cells is unaffected when incubated with up   to 500 mu m of the chelate during 24 h. The helicate permeates   into the cells by endocytosis and locates into lysosomes, which   co-localise with the en-doplasmatic reticulum, as demonstrated by   counterstaining experiments. The relatively long excitation   wavelength allows easy recording of bright luminescent images on   a confocal microscope (lambda(exc) =405 nm). The new lanthanide   bioprobe remains undissociated in the cell medium, and is   amenable to facile derivatisation. Examination of data for seven   Eu-III and Tb-III bimetallic helicates point to shortcomings in   the phenomenological rules Of thumb between the energy gap Delta   E((3)pi pi*-D-5(J)) and the sensitisation efficiency of the   ligands

      Address (URL): WOS:000262886800010