Fabrication of glucose-sensitive TiO2 ultrathin films by molecular imprinting and selective detection of monosaccharides

In this study, we extended the molecular imprinting capability of TiO2 gel to the monosaccharide family. Composite nanofilms were prepared from d-glucose and titanium n-butoxide, Ti(O–nBu)4, on a QCM electrode by the surface sol–gel process. After the d-glucose template was removed, the binding behavior of the template and other monosaccharides (d-mannose, d-galactose and d-fructose) was examined by QCM measurement The d-glucose imprinted TiO2 gel film provided sensitively mass increases for monosaccharides. The largest binding was achieved with d-glucose, showing a maximal binding ratio of 2.3 (λ = Mimp/Mnon-imp, mol/mol) between the imprinted and non-imprinted films. The other six-membered monosaccharide guests gave 44–68% binding efficiencies of that of d-glucose. It is concluded that the imprinted TiO2 gel film could efficiently discriminate the structure of monosaccharide isomers.