Photonic crystal resonator integrated in a microfluidic system

Area of Science:

• Optofluidics
• Photonic Crystals
• Biosensing

Background:

• Label-free detection methods are crucial for real-time analysis in microfluidic systems.
• Photonic crystals offer unique light-matter interaction properties for sensing applications.
• Electrochromatography platforms require sensitive detection for analyzing separated components.

Purpose of the Study:

• To develop and characterize a novel optofluidic system for label-free refractive index detection.
• To integrate a 1D photonic crystal resonator with microfluidic channels for on-column analysis.
• To evaluate the system's sensitivity and detection limits using ethanol-water solutions.

Main Methods:

• Fabrication of a silicon oxynitride-based 1D photonic crystal with integrated waveguides and fluidic channels.
• Utilizing an array of pillars within the microfluidic channel as a resonator for electrochromatography.
• Operating the system at a wavelength of 1.55 micrometers and measuring transmission spectra of ethanol solutions.
• Analyzing linear shifts in resonant wavelengths to determine refractive index sensitivity.

Main Results:

• The optofluidic system demonstrated label-free refractive index detection.
• A maximum sensitivity of 480 nm/RIU (refractive index unit) was achieved.
• A minimum detectable refractive index difference of 0.007 RIU was measured.
• The system successfully analyzed aqueous solutions of ethanol with varying refractive indices.

Conclusions:

• The developed optofluidic system provides a sensitive platform for label-free refractive index sensing.
• The integration of photonic crystals and microfluidics enables on-column detection in electrochromatography.
• This technology holds promise for applications in chemical analysis and diagnostics.