<sub> Of Tio 2 </ Sub> Nanoparticles Porous Film Sensitizing The Piezoelectric Crystal Sensor

In this paper, porous nanocrystalline titanium dioxide films were used to modify the surface of quartz crystal microbalance (QCM), the response of QCM with high roughness layer hi liquid phase was discussed, and the difference between the theoretic value and frequency response measured was illustrated in detail. The obtained QCM sensor has sensitive response to the liquid density and can be expected as a density meter.Composite films of p-cyclodextrin (P-CD) bound to the titanium dioxide nanoparticles were tightly coated on the surface of QCM. The nanoporous structure of films greatly enhanced the active surface area available for p-CD binding by a factor of 25 for a lum-thick-film. Based on multiple linear regression, concentrations of o,p,m-bimethyl-benzene and o,p,m-nitro-phenol have been measured with present sensor. It was possible to detect 0,p,m-bimethybenzen vapors and o,mp,-nitro-phenol in solutions down to ug L-1 and umol?L-1, respectively.The reaction between p-CD and guest molecules was investigated by the thermodynamic and kinetic methods. It is found van der waals forces often predominate, including interaction of permanent and induced dipoles and London dispersion forces, so the process of gust molecular into P-CD ring companies with a great deal of physic sorption.