Love Wave Sensor with High Penetration Depth for Potential Application in Cell Monitoring.

Area of Science:

• Biophysics
• Materials Science
• Biosensing Technology

Background:

• Love wave sensors (L-SAW) are utilized for probing cell monolayers.
• Previous applications focused on focal adhesion points, limiting detection of broader cellular mechanical changes like cytoskeleton viscosity.
• Detecting mechanical changes beyond focal adhesions is crucial for understanding cell behavior.

Purpose of the Study:

• To develop and demonstrate a Love wave sensor with tuned penetration depth and sensitivity for detecting mechanical changes beyond focal adhesion points in cell monolayers.
• To investigate the sensor's capability to measure viscosity changes within cell monolayers.
• To establish a novel tool for cell monolayer characterization.

Main Methods:

• Design and fabrication of a 30 MHz Love wave sensor utilizing a LiNbO3 substrate and an 8-µm SU-8 polymeric guiding layer.
• Modeling of the Love wave sensor using an acoustic transmission line model and interdigital transducer (IDT) response with Campbell's cross-field circuit model.
• Testing the sensor's response to liquids with varying viscosities (0.89–3.3 cP) and with SaOs-2 cells in culture medium.

Main Results:

• The fabricated Love wave sensor exhibited sensitivity to viscosity changes in the range of 0.89–3.3 cP.
• Measurable sensor responses were observed with liquids mimicking cell monolayer viscosity.
• The sensor successfully detected responses from SaOs-2 cells in culture medium.

Conclusions:

• The developed Love wave sensor can detect mechanical changes in cell monolayers beyond focal adhesion points.
• This technology offers a promising approach for developing novel cell-based biosensors.
• The sensor provides a new tool for characterizing the mechanical properties of cell monolayers.