Detection of odorant molecules via surface acoustic wave biosensor array based on odorant-binding proteins.

Area of Science:

• Biosensor technology
• Chemical sensing
• Materials science

Background:

• Odorant molecules are crucial in biological and environmental processes.
• Developing selective and sensitive detection methods for odorants is challenging.
• Surface Acoustic Wave (SAW) devices offer potential for label-free biosensing applications.

Purpose of the Study:

• To develop and characterize a biosensor array for vapor-phase odorant detection.
• To compare the sensing performance of three distinct odorant-binding proteins (OBPs) as sensitive layers for SAW devices.
• To evaluate the array's ability to differentiate between specific odorant molecules.

Main Methods:

• Fabrication of two-port SAW resonators on quartz substrates with aluminum-gold electrodes.
• Coating of SAW devices with three different OBPs (wild-type cow OBP, double mutant cow OBP, wild-type pig OBP) using a droplet method.
• Testing the biosensor array's response to octenol and carvone vapors in nitrogen atmosphere.
• Utilizing an uncoated device for environmental parameter compensation.

Main Results:

• The surface density of OBP layers ranged from 1.18×10⁻⁶ to 2.31×10⁻⁶ kg/m².
• The highest sensitivity for octenol detection (25.9 Hz/ppm) was achieved with the wild-type pig OBP (wtpOBP).
• The highest sensitivity for carvone detection (9.2 Hz/ppm) was achieved with the double mutant cow OBP (dmbOBP).

Conclusions:

• The developed SAW biosensor array demonstrates effective vapor-phase detection of odorant molecules.
• Different OBPs exhibit varying sensitivities towards specific odorants, enabling selective detection.
• This OBP-functionalized SAW biosensor array shows promise for advanced olfactory sensing applications.