Research on tunable distributed SPR sensor based on bimetal film

Area of Science:

• Optoelectronics
• Nanotechnology
• Chemical Sensing

Background:

• Traditional single-point surface plasmon resonance (SPR) sensors face limitations in measurement range.
• Developing multi-channel SPR systems is crucial for efficient and cost-effective biochemical detection.

Purpose of the Study:

• To propose and investigate a symmetric bimetallic film SPR multi-sensor structure.
• To overcome the range limitations of traditional SPR sensors.
• To optimize dual-channel sensing mechanisms for improved performance.

Main Methods:

• Theoretical analysis using thin-film optics theory for prism-excited SPR.
• Simulation using the finite-difference time-domain (FDTD) method.
• Optimization of material composition (silver and gold) and thickness for the bimetallic layer.

Main Results:

• A wider range of dual-channel distributed sensing was achieved by optimizing material and thickness.
• The optimal structure comprised 30 nm silver and 10 nm gold.
• A high quality factor of 5960 was obtained at an incident angle of 78 degrees.
• Maximum sensitivity reached 5.25×10^-5 RIU when analyzing honey solutions.

Conclusions:

• The proposed symmetric bimetallic film SPR multi-sensor structure demonstrates feasibility and practicality.
• This design provides a theoretical foundation for advanced SPR multi-channel distributed sensing systems.
• The system offers potential for significantly reduced biochemical detection costs and increased efficiency.