Hybridization of RNA homopolymers has been employed to verify the possibility of developing a biosensor for nucleic acid based on the thickness-shear mode (TSM) acoustic wave device. The results clearly show that RNA homopolymers can be successfully immobilized onto a PdO electrode surface by chemisorption and that sequence-specific hybridization can be detected. The characterization of TSM sensors upon hybridization of immobilized nucleic acid is achieved through the network analysis of impedance measurements. Multidimensional chemical information regarding nucleic acid hybridization at the interface through correlation with such parameters as the series and parallel resonant frequencies, frequencies at the maximum and minimum impedance, and equivalent circuit elements was obtained. The effect of temperature on RNA homopolymer hybridization has also been examined. The results show that the series resonant frequency increases when single strand Poly C hybridizes to complementary Poly G from solution at low temperature and decreases at high temperature. On the other hand, series resonant frequency always decreases when immobilized Poly A hybridizes to Poly U in the temperature range studied. X-ray photoelectron spectroscopy (XPS) analysis shows that the Poly C . Poly G duplex interacts with the PdO surface, and this dramatically changes the helical structure on the sensor surface, resulting in unexpected frequency increases. The observed results, in large degree, are related to surface hydrophilicity and viscoelastic effects. The strength of the helix-PdO interaction is also temperature-dependent.