Integration of Curved D-Type Optical Fiber Sensor with Microfluidic Chip

Area of Science:

• Optoelectronics
• Biomedical Engineering
• Chemical Sensing

Background:

• Surface Plasmon Resonance (SPR) is a label-free optical technique sensitive to changes in the refractive index near a metal surface.
• Optical Fiber Sensors (OFS) offer remote sensing capabilities and miniaturization potential.
• Microfluidic chips enable precise control and manipulation of small fluid volumes, ideal for biosensing applications.

Purpose of the Study:

• To propose and demonstrate a novel curved D-type optical fiber sensor (OFS) integrated with a microfluidic chip.
• To utilize the OFS as a biosensor for measuring concentrations of various bio-liquids.
• To investigate the potential of this integrated system for monitoring biological samples.

Main Methods:

• Fabrication of a curved D-type optical fiber sensor with a side-polished, gold-coated region.
• Integration of the OFS with a polymethylmethacrylate (PMMA)-based microfluidic chip.
• Excitation of Surface Plasmon Resonance (SPR) using the optical fiber to guide light and measurement of SPR spectra for liquids with varying refractive indices.

Main Results:

• The integrated system successfully recorded SPR spectra for liquids with different refractive indices.
• The biosensor demonstrated a sensitivity on the order of 10^-5 Refractive Index Unit (RIU).
• The system proved effective in detecting and quantifying concentrations of ethanol, methanol, and glucose solutions.

Conclusions:

• The microfluidic chip-integrated OFS is a promising platform for sensitive biosensing.
• This technology can be valuable for real-time monitoring of subtle changes in biological samples.
• Potential applications include blood glucose monitoring, allergen detection, and studying biomolecular interactions.