Visible-NIR surface plasmon resonance sensing technology for high precision refractive index detection

Area of Science:

• Materials Science
• Nanotechnology
• Plasmonics

Background:

• Molybdenum disulfide (MoS2) is a key material in plasmonic technology, particularly for near-infrared (NIR) applications.
• Surface plasmon resonance (SPR) is a sensitive detection technique, but its application in the NIR band faces challenges.
• Transition metal dichalcogenides like MoS2 offer unique optical properties for SPR enhancement.

Purpose of the Study:

• To investigate the physical mechanism of MoS2-excited SPR in the NIR.
• To develop and demonstrate a dual-channel SPR sensor for refractive index (RI) detection operating in both visible and NIR bands.
• To enhance SPR sensing sensitivity and address limitations in multi-channel sensing.

Main Methods:

• Investigated the excitation of SPR using MoS2 films in the NIR.
• Fabricated a cascaded dual-channel SPR sensor utilizing MoS2.
• Performed simulations and experiments to validate sensor performance for RI detection.

Main Results:

• MoS2 films shift the SPR resonance dip towards the NIR, increasing sensitivity compared to the visible band.
• The developed NIR channel achieved a maximum sensitivity of 14600 nm/RIU (37% higher than the visible channel).
• The dual-channel sensor successfully combined high NIR sensitivity with the narrow Full Width at Half Maximum (FWHM) of the visible channel.

Conclusions:

• MoS2 is effective in enhancing SPR sensing performance in the NIR region.
• The proposed cascaded dual-channel sensor offers improved RI detection by leveraging MoS2 for NIR SPR.
• This approach advances SPR sensing technology by improving sensitivity and addressing narrowband issues in multi-channel systems.