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Two-dimensional silicon photonic crystal based biosensing platform for protein detection
Mindy R Lee1, Philippe M Fauchet
1The Institute of Optics, University of Rochester Rochester, New York 14627, USA. mindylee@optics.rochester.edu
Optics Express
|June 18, 2009
Summary
We developed a highly sensitive biosensor using a two-dimensional photonic crystal microcavity. This silicon-based device can detect minuscule molecular masses, as low as 2.5 femtograms, for protein detection.
Area of Science:
- Photonics
- Biosensing
- Nanotechnology
Background:
- Photonic crystal microcavities offer label-free biosensing capabilities.
- Ultrasensitive detection of biomolecules is crucial for early disease diagnosis and research.
Purpose of the Study:
- To theoretically and experimentally demonstrate an ultrasensitive two-dimensional photonic crystal microcavity biosensor.
- To assess the sensor's capability to detect low-mass molecules and protein binding.
Main Methods:
- Fabrication of a two-dimensional photonic crystal microcavity on a silicon-on-insulator wafer.
- Monitoring resonance wavelength shifts due to protein adsorption.
- Theoretical modeling and experimental validation using glutaraldehyde and bovine serum albumin (BSA).
Main Results:
- The biosensor operates with resonance near 1.58 micrometers.
- Protein coating induces a measurable resonance redshift, proportional to molecule size.
- Detection of a monolayer with a mass as low as 2.5 femtograms was achieved.
- Experimental results align with theoretical predictions and ellipsometric measurements.
Conclusions:
- The demonstrated photonic crystal microcavity biosensor exhibits ultrasensitive detection capabilities.
- The device shows promise for label-free, low-mass molecule detection in biological and chemical applications.
- This technology can be advanced for various point-of-care diagnostic tools.
