title: Host-guest complexation studied by fluorescence correlation spectroscopy: adamantane-cyclodextrin inclusion.
abstract: The host-guest complexation between an Alexa 488 labelled adamantane derivative and beta-cyclodextrin is studied by Fluorescence Correlation Spectroscopy (FCS). A 1:1 complex stoichiometry and a high association equilibrium constant of K = 5.2 x 10(4) M(-1) are obtained in aqueous solution at 25 degrees C and pH = 6. The necessary experimental conditions are discussed. FCS proves to be an excellent method for the determination of stoichiometry and association equilibrium constant of this type of complexes, where both host and guest are nonfluorescent and which are therefore not easily amenable to standard fluorescence spectroscopic methods.
authors.affiliation: Departamento de Química Física, Universidade de Santiago de Compostela, Lugo, Spain. daniel.granadero@usc.es
authors.forename: Daniel
authors.initials: D
authors.lastname: Granadero
authors.forename: Jorge
authors.initials: J
authors.lastname: Bordello
authors.forename: Maria Jesus
authors.initials: MJ
authors.lastname: Pérez-Alvite
authors.forename: Mercedes
authors.initials: M
authors.lastname: Novo
authors.forename: Wajih
authors.initials: W
authors.lastname: Al-Soufi
mesh_terms: D000218:Adamantane / Q000737:chemistry; D003505:Cyclodextrins / Q000737:chemistry; D015394:Molecular Structure; D013050:Spectrometry, Fluorescence; D013194:Staining and Labeling
chemical_list: D003505:Cyclodextrins; D000218:Adamantane