title: Rhenium bipyridine complexes for the recognition of glucose.
abstract: Bipyridine ligands containing pendant methyl, amino, and amino-boronic acid groups were synthesized. Coordination complexes of these ligands with rhenium were prepared straightforwardly and in good yield. The fluorescence behavior of the Re complexes was studied as a function of pH and exposure to various concentrations of glucose. The methyl bipyridine complex showed no change in fluorescence with pH, the amino derivative showed a rapid decrease from low pH to neutral, and the amino-boronate derivative showed little change from pH 4 to 10. Fluorescence quenching was observed at high pH as expected on the basis of a photoinduced electron transfer (PET) signaling mechanism. This behavior can be explained on the basis of the first oxidation and reduction potentials of these complexes. Glucose testing showed a significant dependence on the solvent system used. In pure methanol, the rhenium boronate complex exhibited a 55% fluorescence intensity increase upon increasing glucose concentration from 0 to 400 mg/dL. However, in 50 vol % methanol/phosphate buffered saline, none of the complexes showed significant response in the glucose range of physiological interest.
authors.affiliation: University of California, Lawrence Livermore National Laboratory, P.O. Box 808, L-092, Livermore, California 94551, USA. dcary@pcpy.com
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Cary
authors.forename: Natasha P
authors.initials: NP
authors.lastname: Zaitseva
authors.forename: Kelsey
authors.initials: K
authors.lastname: Gray
authors.forename: Kira E
authors.initials: KE
authors.lastname: O'Day
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Darrow
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Lane
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Peyser
authors.forename: Joe H
authors.initials: JH
authors.lastname: Satcher
authors.forename: William P
authors.initials: WP
authors.lastname: Van Antwerp
authors.forename: A J
authors.initials: AJ
authors.lastname: Nelson
authors.forename: John G
authors.initials: JG
authors.lastname: Reynolds
mesh_terms: D002384:Catalysis; D004563:Electrochemistry; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry; D005947:Glucose / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D008024:Ligands; D008956:Models, Chemical; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010084:Oxidation-Reduction; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry; D012211:Rhenium / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D008024:Ligands; D009942:Organometallic Compounds; D011725:Pyridines; D012211:Rhenium; D005947:Glucose