title: A Self-Assembled Sensor for Carbohydrates on the Surface of Cyclodextrin Vesicles.
abstract: A supramolecular carbohydrate sensor was prepared by self-assembly of unilamellar bilayer vesicles of amphiphilic β-cyclodextrin with a boronic acid-adamantane conjugate (PBA-AD), which binds strongly to β-cyclodextrin through host-guest interactions (Ka≈4×104m-1), so the vesicle surface exhibits multiple boronic acid receptors for carbohydrates. The binding of diols to the functionalized vesicles was tested with alizarin red S (ARS) as a reporter dye by using fluorescence and UV/Vis spectroscopy. Analysis of the competitive binding of monosaccharides revealed pH-dependent (pH 7.4-10.1) binding constants in the range of 100-3000 m-1for d-fructose and 5-400 m-1for d-glucose. Interestingly, the self-assembled sensor showed fluorescence intensity enhanced by about fivefold and a binding affinity to the reporter dye increased by about eightfold in comparison to PBA-AD and ARS without vesicles. This is attributed to increased local concentration of ARS and PBA-AD on the surface of the vesicles. Detection of d-fructose and d-glucose was possible in the physiologically relevant range in dilute aqueous solution.
authors.affiliation: Organic Chemistry Institute and Graduate School of Chemistry, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Himmelein
authors.affiliation: Organic Chemistry Institute and Graduate School of Chemistry, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany.
authors.forename: Bart Jan
authors.initials: BJ
authors.lastname: Ravoo
mesh_terms: D000218:Adamantane / Q000737:chemistry; D000880:Anthraquinones / Q000737:chemistry; D001897:Boronic Acids / Q000737:chemistry; D002151:Calorimetry; D005632:Fructose / Q000032:analysis / Q000737:chemistry; D005947:Glucose / Q000032:analysis / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D009005:Monosaccharides / Q000032:analysis / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry; D013816:Thermodynamics; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D000880:Anthraquinones; D001897:Boronic Acids; D009005:Monosaccharides; D047392:beta-Cyclodextrins; D005632:Fructose; C004468:Alizarin Red S; D005947:Glucose; C031215:betadex; D000218:Adamantane
keywords: boronic acids; carbohydrates; host-guest systems; sensors; vesicles