Lossy Mode Resonance Based Microfluidic Platform Developed on Planar Waveguide for Biosensing Applications.

Area of Science:

• Optoelectronics
• Biomedical Engineering
• Materials Science

Background:

• Resonance phenomena-based optical biosensors are gaining relevance.
• Optical fiber sensors for Lossy Mode Resonance (LMR) have drawbacks like complex handling and polarization control.
• Planar waveguides offer a more robust, cost-effective, and easier-to-handle alternative.

Purpose of the Study:

• To propose and evaluate a microfluidic LMR-based planar waveguide platform for biosensing.
• To demonstrate the platform's capability in detecting specific biomolecular interactions.
• To overcome the limitations associated with traditional optical fiber LMR sensors.

Main Methods:

• A planar waveguide platform was fabricated using a titanium dioxide (TiO2) thin-film for resonance generation.
• Immobilization of immunoglobulin G (IgG) antibodies via covalent binding.
• Detection of anti-immunoglobulin G (anti-IgG) at concentrations from 5 to 20 μg/mL in PBS buffer.

Main Results:

• The LMR wavelength exhibited a shift to higher values with increasing anti-IgG concentration.
• The proposed system successfully detected the binding of IgG/anti-IgG.
• A calibration curve was established based on experimental data from three assay repetitions.

Conclusions:

• A novel microfluidic LMR biosensing platform on planar substrates was successfully developed.
• The platform demonstrates potential for sensitive and reliable biosensing applications.
• This work presents a significant advancement over optical fiber-based LMR sensors.