A surface acoustic wave biosensor for interrogation of single tumour cells in microcavitiesElectronic supplementary information (ESI) available: SUS and OT conceived and designed the devices and the study, performed the experiments, and co-wrote the manuscript. SUS fabricated the devices. ZA, SR, RD, and RJC provided the cell cultures. See DOI: 10.1039/c5lc01212k

• Main Authors: Senveli, Sukru U, Ao, Zheng, Rawal, Siddarth, Datar, Ram H, Cote, Richard J, Tigli, Onur
• Format: Article
• ISSN: 1473-0197; 1473-0189
• DOI: 10.1039/c5lc01212k

In this study, biological cells are sensed and characterized with surface acoustic wave (SAW) devices utilising microcavities. After tumour cells in media are transported to and trapped in microcavities, the proposed platform uses SAW interaction between the substrate and the cells to extract their mechanical stiffness based on the ultrasound velocity. Finite element method (FEM) analysis and experimental results show that output phase information is an indicator of the stiffness modulus of the trapped cells. Small populations of various types of cells such as MCF7, MDA-MB-231, SKBR3, and JJ012 were characterized and characteristic moduli were estimated for each cell population. Results show that high frequency stiffness modulus is a possible biomarker for aggressiveness of the tumour and that microcavity coupled SAW devices are a good candidate for non-invasive interrogation of single cells. Tumour cells are acoustically interrogated using Rayleigh type SAW devices where an embedded microcavity facilitates direct interaction between the cells and the surface waves.