An imprinted fluorescent chemosensor prepared using dansyl-modified β-cyclodextrin as the functional monomer for sensing of cholesterol with tailor-made selectivity

A novel cholesterol-imprinted fluorescent chemosensor was synthesized by molecular imprinting technique. In the molecular imprinting, dansyl-modified β-cyclodextrin (β-CD-en-DNS) was used as the functional monomer that formed a complex with cholesterol by inclusion interactions. The membrane chemosensor responded to the addition of cholesterol via a “turn off” mode. The chemosensor has selectivity for cholesterol, which differs from that of the monomer β-CD-en-DNS. This tailor-made response of the chemosensor demonstrated that imprinted binding sites were formed. The 2D 1H NMR experiment indicated that one cholesterol molecule interacted with two β-CDs to form binding receptors for the analyte. In the present study, the fluorescence change of dansyl groups with the variation of the environment due to the in-out of the CD cavity was utilized to signal the binding of the analytes. This sensing mechanism can be utilized by the compounds which have inclusion interaction with β-CD. It provided more applications in the fabrication of imprinted fluorescent chemosensors by molecular imprinting technique. Meanwhile, because β-CD is water soluble and can include neutral compounds, this imprinted chemosensor has advantage in the recognition of organic analytes in the aqueous solution.