Bimetallic nanodisk-based fiber-optic plasmonic nanoprobe for gas detection

Area of Science:

• Nanotechnology
• Materials Science
• Optical Engineering

Background:

• Plasmonic nanostructures offer unique optical properties for sensing applications.
• Optical fiber sensors provide remote and real-time monitoring capabilities.
• Bimetallic nanostructures can enhance sensitivity and functionality compared to monometallic ones.

Purpose of the Study:

• To develop and characterize gold-palladium bimetallic nanodisks on optical fibers for enhanced sensing.
• To investigate the influence of structural parameters on plasmonic properties and refractive index sensitivity.
• To evaluate the performance of the developed nanoprobe for hydrogen sensing.

Main Methods:

• Fabrication of gold-palladium bimetallic nanodisks on optical fibers using nanosphere lithography and chemical growth.
• Optimization of nanostructure density, growth solution concentration, and growth time.
• Characterization of structural features, plasmonic efficiency, and refractive index sensitivity.
• Hydrogen sensing experiments at various concentrations.

Main Results:

• Achieved high refractive index sensitivity due to large surface area and enhanced plasmonic efficiency from the palladium shell.
• Demonstrated hydrogen sensing with a detection limit of 0.125% and a signal-to-noise ratio of 24.2 dB.
• Exhibited good response time and low hysteresis in hydrogen sensing, outperforming other sensors.

Conclusions:

• The developed fiber-optic plasmonic nanoprobe, fabricated using cost-effective methods, shows high performance for refractive index and hydrogen sensing.
• The nanostructure's design and material composition are crucial for achieving enhanced plasmonic efficiency and sensitivity.
• This technology holds potential for remote sensing applications in dangerous environments, contributing to safety management in the clean energy sector.