Communication. Network analysis: acoustic energy transmission detection of polynucleotide hybridization at the sensor–liquid interface

Abstract

Palladium has been sputtered onto the surface of gold-plated thickness-shear mode acoustic wave sensors. Adsorption of polynucleotides onto the PdO surface is confirmed by X-ray photoelectron spectroscopy and by gas-phase sensor measurements. Hybridization of complementary strands of polynucleotide at the device–liquid interface results in series resonant frequency signals (network analysis) that are significantly higher than expected from mass-based responses. This observation is interpreted in terms of the perturbation of acoustic energy transmission by changes in interfacial properties on hybridization. Preliminary measurements of changes in motional resistance from network analysis are also presented.