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Single-channel Mach-Zehnder interferometric biochemical sensor based on two-lateral-mode spiral waveguide
Optics Express
|November 18, 2014
Summary
We developed a compact Mach-Zehnder interferometric (MZI) biochemical sensor using a spiral waveguide for high sensitivity. This silicon-based sensor accurately detects low concentrations of biomolecules, like biotin-streptavidin interactions.
Area of Science:
- Photonics
- Biomedical Engineering
- Materials Science
Background:
- Mach-Zehnder interferometers (MZIs) are sensitive optical devices.
- Compact and high-sensitivity biochemical sensors are crucial for diagnostics.
- Fabrication of complex waveguide structures can be challenging.
Purpose of the Study:
- To propose and demonstrate a novel single-channel MZI biochemical sensor.
- To utilize a two-lateral-mode spiral waveguide for enhanced sensitivity and compactness.
- To investigate the sensor's performance in silicon waveguides.
Main Methods:
- Fabrication of the MZI sensor using single-step lithography and etching.
- Integration of a two-lateral-mode spiral sensing waveguide.
- Characterization of bulk and surface sensitivity.
- Verification of biosensing capability via biotin-streptavidin interaction assays.
Main Results:
- Demonstrated a compact MZI sensor with a spiral waveguide.
- Achieved high bulk sensitivity (461.6 π/RIU) and surface sensitivity (1.135 π/ng mm⁻²).
- Successfully verified biosensing capabilities through concentration-dependent biotin-streptavidin binding detection.
Conclusions:
- The proposed two-lateral-mode spiral waveguide MZI sensor offers a promising platform for sensitive and compact biochemical sensing.
- The simple fabrication process and small sample volume requirement make it suitable for various applications.
- The sensor's performance in detecting molecular interactions is validated.
