Abstract: An equation for determining the equilibrium association constant (K_A) of cyclodextrin inclusion complex with fluorescence anisotropy is derived and used to determine KAof pyrene-B-cyclodextrin inclusion complex. The existing forms of cyclodextrin inclusion complex in solution, the interaction type of host with guest, and the possibility of application of B-cyclodextrin in the analysis of metal ions using naphthalene derivative as a ligand are discussed based on the equation derived along with the curve of fluorescence anisotropy versus cyclodextrin concentration of guest/cyclodextrin system.

Key words: Fluorescence anisotropy, Cyclodextrin inclusion complex, Association constant, Existing form, Host-guest interaction