Nanoparticle functionalised small-core suspended-core fibre - a novel platform for efficient sensing.

Area of Science:

• Optofluidics
• Plasmonics
• Bioanalytical Chemistry
• Nanotechnology

Background:

• Detecting trace amounts of target molecules is crucial for disease diagnostics and environmental analysis.
• Plasmonic waveguides combined with microfluidics offer a promising sensing approach.
• Existing methods require improvement in sensitivity and ease of use for invasive bioanalytics.

Purpose of the Study:

• To introduce a novel, fully integrated optofluidic sensing platform.
• To demonstrate efficient refractive index sensing using suspended-core fibers with plasmonic nanoparticles.
• To enable real-time analyte monitoring for molecular disease diagnostics and environmental science.

Main Methods:

• Development of suspended-core fibers with immobilized plasmonic nanoparticles (gold nanospheres) around the guiding core.
• Integration of microfluidic channels adjacent to the optical core.
• Characterization of nanoparticle coverage densities and refractive index sensitivities.

Main Results:

• Achieved over two orders of magnitude of nanoparticle coverage densities.
• Demonstrated high refractive index sensitivity of 170 nm/RIU for aqueous analytes.
• Utilized millimetre-long sample lengths with extremely small optical cores.

Conclusions:

• The proposed concept offers a fully integrated optofluidic sensing system.
• The platform requires minimal sample volumes and allows for real-time monitoring.
• This technology is highly relevant for invasive bioanalytics, molecular disease diagnostics, and environmental science.