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Silicon coupled-resonator optical-waveguide-based biosensors using light-scattering pattern recognition with
Jiawei Wang1, Zhanshi Yao1, Ting Lei1
1Photonic Device Laboratory, Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
Scientific Reports
|December 19, 2014
Summary
This study presents a novel chip-scale biosensor using a coupled-resonator optical-waveguide (CROW) for sensitive, portable refractive index detection. The spatial domain sensing method avoids equipment noise, enabling robust point-of-care diagnostics.
Area of Science:
- Photonics
- Nanotechnology
- Biosensing
Background:
- Traditional microcavity biosensors require bulky, precise equipment, limiting point-of-care applications.
- Spectral domain measurements are susceptible to equipment noise and lack portability.
Purpose of the Study:
- To demonstrate a portable, equipment-noise-tolerant biosensor using coupled-resonator optical-waveguide (CROW) technology.
- To develop a spatial domain sensing scheme for refractive index detection.
Main Methods:
- Utilized a silicon-on-insulator chip with an 8-microring CROW.
- Excited the CROW at a fixed wavelength and analyzed out-of-plane light-scattering patterns.
- Employed a pattern-recognition algorithm correlating scattering patterns to refractive index changes.
Main Results:
- Achieved a refractive index change (Δn) detection of ~1.5 × 10⁻⁴ refractive index units (RIU).
- Demonstrated a high sensitivity of ~752 RIU⁻¹.
- Reported a noise-equivalent detection limit of ~6 × 10⁻⁶ RIU.
Conclusions:
- The CROW-based biosensor offers a promising alternative for sensitive, portable, and noise-tolerant refractive index sensing.
- Spatial domain analysis of light scattering provides a robust method for biosensing applications.
