Host-Guest Complexation Studied by Fluorescence Correlation Spectroscopy: Adamantane–Cyclodextrin Inclusion

• Main Authors: Wajih Al-Soufi, Mercedes Novo, Maria Jesus Pérez-Alvite, Jorge Bordello, Daniel Granadero
• Format: Article
• Language: English
• Published: MDPI AG 2010-01-01
• Series: International Journal of Molecular Sciences
• Subjects: fluorescence correlation spectroscopy; host-guest chemistry; adamantane; cyclodextrin
• Online Access: http://www.mdpi.com/1422-0067/11/1/173/
• ISSN: 1422-0067

The host-guest complexation between an Alexa 488 labelled adamantane derivative and β-cyclodextrin is studied by Fluorescence Correlation Spectroscopy (FCS). A 1:1 complex stoichiometry and a high association equilibrium constant of K = 5.2 × 104 M-1 are obtained in aqueous solution at 25 °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.