Fiber surface modification technology for fiber-optic localized surface plasmon resonance biosensors

Area of Science:

• Nanotechnology
• Materials Science
• Biomedical Engineering

Background:

• Optical fiber sensors are crucial for biosensing applications.
• Localized surface plasmon resonance (LSPR) using gold nanoparticles enhances sensor sensitivity.
• Surface modification of optical fibers is key to developing robust biosensors.

Purpose of the Study:

• To present a new fiber surface modification technique for biosensors.
• To investigate the self-assembly of star-shaped gold nanoparticles on tapered optical fibers.
• To evaluate the sensitivity and stability of modified optical fiber sensors.

Main Methods:

• Seed-mediated synthesis of star-shaped gold nanoparticles.
• Self-assembly of gold nanoparticles on tapered optical fibers using amino- and mercapto-silane coupling agents (APTMS and MPTMS).
• Characterization of transmission spectra in varying ethanol and gentian violet concentrations.

Main Results:

• Successful surface modification verified by transmission spectra of APTMS-modified fibers.
• Gold nanoparticle-modified fibers showed sensitivity to the dielectric properties of the surrounding medium.
• MPTMS modification resulted in a firmer gold nanoparticle surface compared to APTMS, enhancing sensor stability.

Conclusions:

• Star-shaped gold nanoparticles can be effectively self-assembled on optical fibers using silane coupling agents.
• The developed optical fiber sensors exhibit sensitivity to changes in the surrounding medium.
• Mercapto-silane coupling agents provide a more stable surface modification for gold nanoparticle-based optical fiber biosensors.