Notice of Removal: Chemical and biological sensing using acoustic wave propagation and nano-scale phenomena

Abstract

Surface acoustic wave propagation in piezoelectric substrates is combined with nano-scale phenomena in sensing layer materials to realize practically viable chemical and biological sensors in our group. Ab initio electronic structure, molecular dynamics and finite element models are constructed to design these sensors and sensing materials, and understand sensing mechanisms at multiple length and time scales. Several design advances to the surface acoustic wave (SAW) device to improve sensitivity, enable non-specific binding removal and increase incubation times will be presented. One result of these studies is a SAW biosensor in which Rayleigh and Love waves are propagated in orthogonal directions to achieve mixing, non-specific binding removal and sensing in the same device for biosensing applications. Improved incubation times, removal of non-specifically bound proteins to improve sensitivity, reduce false determinations and improve selectivity, and sensing are simultaneously realized in devices constructed in Langasite and ST quartz, and results will be presented. Several applications of SAW devices in chemical and biological sensing wherein nano-scale phenomena in sensing materials is utilized to improve sensor properties will be presented. In one application, interaction of hydrogen with a palladium film is replaced with interaction with palladium nanoparticles loaded on flexible single-walled carbon nanotube (SWCNT) surfaces. This allows for a robust hydrogen sensor using acoustic wave devices. In the second application, enhancement of luminescence by silver nanocubes is leveraged to construct an immunofluorosensor which is orders of magnitude more sensitive than without this plasmonic enhancement. Combined with a Rayleigh wave SAW device, a sensitive, selective and fast-responding immunofluorosensor is realized. In a third application, carcionoembryonic antigen (a cancer biomarker) is detected at clinically-relevant pg/ml levels with a Love wave device using gold nanoparticle-based nanoprobes. Details will be presented in this talk.