Inverted Cucurbit[7]uril-induced supramolecular fluorescence enhancement in hemicyanine dye and its analysis application

The host − guest interaction between inverted cucurbit[7]uril (iQ[7]) and hemicyanine dye (4-ASP) under different pH conditions was studied. We have found that styryl groups can occupy the cavity of iQ[7], leading to inverted cucurbit[7]uril-induced supramolecular fluorescence enhancement on the basis of host − guest recognition. The supramolecular dye complexes could be reversibly switched under acidic and neutral conditions. Moreover, the “OFF − ON − OFF” behavior of the host − guest complexes with the alternating addition of H+ and OH– has been utilized to develop a model INHIBIT logic gate. Furthermore, [email protected][7] was responsive to specific chemical stimuli.