Fabrication of a Bare Optical Fiber-Based Biosensor

Area of Science:

• Optoelectronics
• Biomedical Engineering
• Nanotechnology

Background:

• Optical fiber sensors offer label-free detection capabilities.
• Surface Plasmon Resonance (SPR) is a sensitive technique for detecting changes at interfaces.
• Kretschmann's configuration is a standard method for exciting SPR.

Purpose of the Study:

• To develop and characterize a bare optical fiber-based biosensor.
• To measure the refractive index of liquids and the binding kinetics of biomolecules.
• To demonstrate the sensor's potential for real-time biomolecular interaction analysis.

Main Methods:

• Fabrication of a bare optical fiber coated with a gold film.
• Utilizing Kretschmann's configuration for Surface Plasmon Resonance (SPR) excitation.
• Measuring spectral shifts in response to varying refractive indices and biomolecular binding.

Main Results:

• The biosensor achieved high sensitivity for refractive index measurements (10^-4~10^-5 RIU).
• Real-time monitoring of protein binding kinetics was successfully demonstrated.
• The sensor performance was validated using methanol and ethanol solutions.

Conclusions:

• The proposed bare optical fiber biosensor is a promising platform for sensitive biomolecular detection.
• The sensor enables label-free, real-time analysis of binding kinetics.
• Future applications include in situ monitoring of allergens, antibody-antigen interactions, and circulating tumor cells.