Molecularly Imprinted TiO2 Thin Film by Liquid Phase Deposition for the Determination of l-Glutamic Acid

For the first time, the feasibility of a molecularly imprinted liquid phase deposition (LPD) thin film has been demonstrated. Thin films of titanium oxide imprinted with l-glutamic acid were prepared by the LPD method on a gold-coated quartz crystal microbalance. The imprinted molecule could be removed upon treatment with immersion in deionized water. A sensor was developed on the basis of this method and showed good sensitivity, selectivity, and reproducibility to the template molecule. An equation was deduced to characterize the interaction between molecularly imprinted films and the template by virtue of Scatchard analysis. X-ray photoelectron spectroscopy was introduced to show the evidence for the molecular imprinting phenomenon. The linear relationship between the frequency shifts and the concentration of analyte in the range of 10−200 μM was obtained. LPD proves to be a powerful method for imprinting titanium oxide thin films.