Integrated Love Wave Device Dedicated to Biomolecular Interactions Measurements in Aqueous Media

Area of Science:

• Electro-acoustic biosensing
• Surface Acoustic Wave (SAW) devices
• Biophysical measurements

Background:

• Mass-sensitive electro-acoustic devices like SAW micro-balances are suitable for biosensors operating in aqueous media.
• Fluid viscosity can reduce signal dynamics in surface wave transducers, limiting biosensor performance.
• Existing biosensor designs often struggle with interference from biological fluid properties.

Purpose of the Study:

• To develop a specific grating configuration for SAW biosensors to reduce the influence of fluid viscosity.
• To design and fabricate a dedicated liquid cell using SU-8 photo-resist to isolate the electro-active transducer.
• To optimize the sensor's sensing area for enhanced gravimetric sensitivity.

Main Methods:

• Utilized a novel grating configuration to mitigate viscosity effects on SAW transducers.
• Engineered a protective liquid cell using SU-8 photo-resist to prevent liquid-transducer contact.
• Optimized the sensor's sensing area for improved gravimetric sensitivity.

Main Results:

• Demonstrated a reduction in the influence of fluid viscosity on the sensor's signal dynamics.
• Successfully isolated the electro-active transducer from the tested liquids using the SU-8 cell.
• Achieved enhanced gravimetric sensitivity in the optimized sensing area.
• Illustrated sensor operation by detecting bovine serum albumin (BSA) adsorption.

Conclusions:

• The developed SAW biosensor design effectively overcomes limitations imposed by fluid viscosity.
• The integrated liquid cell and optimized grating configuration enhance sensor robustness and sensitivity.
• This approach advances the development of reliable biosensors for biological fluid analysis.