On chip glucose sensing using guided waves at terahertz frequencies.

Area of Science:

• Terahertz (THz) spectroscopy
• On-chip sensing technologies
• Biosensor development

Background:

• Label-free detection of biomolecules is crucial for various applications.
• Terahertz frequencies offer unique interaction properties with matter.
• Existing THz sensing methods often require free-space setups.

Purpose of the Study:

• To demonstrate an integrated, on-chip sensor for anhydrous D-glucose detection.
• To explore the use of coplanar striplines (CPS) at THz frequencies for material sensing.
• To establish a foundation for on-chip THz sensing of other materials.

Main Methods:

• Fabrication of a coplanar stripline (CPS) on a silicon nitride membrane.
• Measurement of transmission response using a modified THz-TDS setup with D-glucose proximity.
• Utilizing frequency-dependent changes in effective permittivity for detection.
• Employing a modified Lorentz model for simulation of attenuation coefficients.

Main Results:

• Observed distinct absorption signatures for D-glucose at 1.42 THz and 2.07 THz.
• Achieved label-free detection of anhydrous D-glucose.
• Measurement results showed good agreement with simulations and literature.
• Validated the effectiveness of on-chip THz sensing.

Conclusions:

• The developed on-chip CPS sensor effectively detects anhydrous D-glucose at THz frequencies.
• This work confirms the viability of integrated THz sensing for specific biomolecules.
• Paves the way for developing on-chip THz sensors for a broader range of materials.