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Dry Film Photoresist-based Electrochemical Microfluidic Biosensor Platform: Device Fabrication, On-chip Assay Preparation, and System Operation
Published on: September 19, 2017
Biochemical signal detection in miniaturized fluidic systems by integrated microresonator
Jack Barnes1, Olivia Chiu, James M Fraser
1Dept. of Chemistry, Queen's University, Kingston, ON, Canada. jbarnes@chem.queensu.ca
Summary
This study introduces a low-cost optical sensor on a polymer microfluidic chip for biochemical analysis. It utilizes a high-quality silica microsphere resonator to detect analytes with high sensitivity.
Area of Science:
- Optoelectronics
- Biochemical Sensing
- Microfluidics
Background:
- Biochemical analysis requires sensitive and parallel detection methods.
- Microfluidic chips offer platforms for miniaturized analytical systems.
- Optical resonators are sensitive to environmental changes, making them suitable for sensing.
Purpose of the Study:
- To propose a low-cost, highly parallel optical sensor for biochemical analysis.
- To integrate a high-finesse optical resonator into a polymer microfluidic chip.
- To demonstrate analyte detection using whispering gallery modes in silica microspheres.
Main Methods:
- Fabrication of high-quality silica microspheres (approx. 300 micrometers).
- Excitation of low-loss whispering gallery modes via evanescent coupling at 1550 nm and 544 nm.
- Determination of quality factors (Q) and ring down times from phase shift measurements (below 300 kHz modulation).
Main Results:
- Achieved high quality factors (Q ~ 10^6) and ring down times up to 53.8 ± 0.6 ns.
- Demonstrated sensitivity of whispering gallery modes to microresonator environment changes.
- Successfully measured sensor parameters using phase shift analysis instead of traditional time-domain studies.
Conclusions:
- The proposed optical sensor integrated into a polymer microfluidic chip is a viable low-cost solution for biochemical analysis.
- Silica microsphere resonators exhibit excellent sensing capabilities due to their high Q-factor and sensitivity.
- Phase shift measurements provide an effective method for characterizing resonator performance for sensing applications.
