Synthesis and surface grafting of a β-cyclodextrin dimer facilitating cooperative inclusion of 2,6-ANS

A novel β-cyclodextrin (β-CD) dimer was synthesized and surface-grafted by click chemistry onto azide-functionalized quartz surfaces in order to introduce the cooperative features of the β-CD dimer to solid surfaces. Using NMR and fluorescence spectroscopy, it is shown that the free β-CD dimer forms a 1:1 complex with the fluorescent guest molecule, 2-anilinonaphthalene-6-sulfonic acid (otherwise known not to form 1:2 complexes with parent β-CD), with an apparent association constant of 7300 M(-1). Further, it is shown using total internal reflection fluorescence spectroscopy that the inclusion of the fluorescent guest into both cavities of the β-CD dimer is maintained when grafted onto a solid surface.