Highlights the trapping of NO2 molecules in the porous structure and thus making the film stiffer. Moreover, the Pb(NO3)2-treated sensor showed good stability and selectivity at room temperature.

A love-mode surface acoustic wave (SAW) biosensor based on ST-cut quartz was developed for highly selective and label-free detection of carcinoembryonic antigen (CEA).The delay line area of an interdigital transducer (IDT) based SAW device was coated with gold and then chemically modified through thioglycolic acid-EDC/NHS reaction mechanism. A self-assembled monolayer of anti-CEA was further immobilized on the bioreceptors through the coupling layer. The biosensing capability of the SAW device was evaluated using solutions of CEA with various concentrations and limit of detection was obtained at 0.31 ng/ml of CEA, which is better than the results reported by the literatures available for CEA detection using SAW device. The real-time detection capability of the biosensor was evaluated using clinical serum samples and selectivity was evaluated using mixed solutions of CEA with other common tumor marking proteins. Long-term stability of the biosensor was also evaluated over a period of 30 days and the biosensing performance has shown only 8% decrease in performance within the whole period. The binding of CEA onto the bioreceptor was evaluated through Langmuir and Freundlich sorption isotherm kinetic studies as well.

Shear horizontal surface acoustic waves (SH-SAWs) have been regarded as good candidates for liquid sensing applications but are inefficient in fluid manipulation due to a minimal fluid coupling between the fluid and acoustic waves. However, in this letter, a vertical jetting function was realized using the SH-SAW generated from a 36° Y-X LiTaO3 SAW device. The jetting of the droplet induced by the SH-SAWs was observed nearly along the vertical direction, and the aspect ratio of the liquid beam is proportional to the applied power before breaking up, which is dramatically different from those generated from the conventional Rayleigh SAWs. By conducting theoretical simulation and experimental investigation on the SH-SAWs systematically, we concluded that the wave/energy pressure dissipated into the sessile droplets causes this vertical ejection on the device surface.

No abstract