Coupled resonance in SH-SAW resonator with S1813 micro-ridges for high mass sensitivity biosensing applications

• Published in: Sensors and actuators. B, Chemical Chemical, 2018-11, Vol.273, p.288-297
• Main Authors: Trivedi, Shyam, Nemade, Harshal B.
• Format: Article
• Language: English
• Subjects: Biosensor; Biosensors; Biotin; Coupled resonance; Finite element analysis; Finite element method; Photoresist; Proteins; Ridge; Ridges; SAW; Sensitivity; Substrates; Surface acoustic wave devices; Wave propagation
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2018.06.040

[Display omitted] •3D FE simulation and fabrication of SH-SAW resonator comprising S1813 micro-ridges.•Analysis of coupled resonance effect and its potential application for biosensing.•At critical ridge height, average stress and mass sensitivity of device increases.•Polymer ridges are biofunctionalized to detect biotin of different concentrations.•Ridge-based device offers mass sensitivity three times greater than layered device. The paper presents 3D finite element simulation and fabrication of SH-SAW resonator to investigate coupled resonance in the device with S1813 micro-ridges and its potential use as a sensitive biosensor. Polymer ridges of fixed width and various heights are designed along the wave propagation direction on the surface of the resonator. The coupled resonance effect showing a sharp decrease and an increase in the resonance frequency of the device is attained at a critical ridge height of 2000 nm and the same configuration is used for specific detection of biotin. The mass sensitivity of the device becomes maximum at coupled resonance along with an increase in the area-averaged stress at the interface between the ridge and the substrate. The S1813 ridges are silanized by APTES and the subsequent protein attachment is confirmed by confocal microscopy. Different concentrations of biotin solution are applied to the sensing and reference devices immobilized with avidin and BSA, respectively. The device offers high mass sensitivity of 6.4 kHz/(μg/mL) which is about three times greater than the mass sensitivity offered by a layered SH-SAW device.