Quantitative protein sensing with germanium THz-antennas manufactured using CMOS processes

Area of Science:

• Terahertz (THz) sensing
• Plasmonics
• Biosensing

Background:

• CMOS manufacturing enables integrated, low-cost sensing platforms.
• Terahertz (THz) technology offers unique sensing capabilities.
• Label-free biosensing is crucial for diagnostics and research.

Purpose of the Study:

• To demonstrate a label-free protein sensing platform operating in the THz range.
• To investigate the performance of germanium plasmonic antennas on silicon (Si) and silicon-on-insulator (SOI) substrates.
• To assess the sensitivity and potential for low-cost lab-on-a-chip biosensors.

Main Methods:

• Fabrication of highly doped germanium plasmonic antennas on Si and SOI substrates.
• Characterization of antenna response to varying concentrations of Bovine Serum Albumin (BSA).
• Analysis of sensitivity and saturation levels of the THz sensing platform.

Main Results:

• The germanium plasmonic antennas exhibited a linear response to BSA concentration, saturating above 20 mg/mL.
• Germanium antennas on SOI substrates demonstrated a two-fold increase in sensitivity compared to those on Si substrates.
• The achieved sensitivity of 6 GHz/(mg/mL) is four times higher than reported for metal-based metamaterials.

Conclusions:

• The developed THz sensing platform using germanium antennas on SOI substrates shows significant potential for highly sensitive, label-free protein detection.
• This technology could lead to the development of cost-effective, integrated lab-on-a-chip biosensing devices.
• The enhanced sensitivity achieved paves the way for advanced THz biosensing applications.