Two-Dimensional Layered Nanomaterial-Based One-Dimensional Photonic Crystal Refractive Index Sensor

Area of Science:

• Photonics
• Nanomaterials Science
• Biosensing

Background:

• One-dimensional photonic crystal (1DPC) sensors are emerging as alternatives to traditional surface plasmon resonance (SPR) sensors.
• 1DPCs offer a higher interaction volume for detecting larger molecules and particles.
• Two-dimensional layered nanomaterials like graphene and dichalcogenides exhibit high refractive index sensitivity due to absorption and adsorption properties.

Purpose of the Study:

• To propose and analyze a 1DPC sensor configuration using layered nanomaterials and silicon.
• To evaluate the performance of this 1DPC sensor by comparing it with a 1DPC using poly methyl methacrylate (PMMA).
• To assess the suitability of 1DPC sensors for large molecule detection compared to SPR sensors.

Main Methods:

• Fabrication of a 1DPC sensor with alternating layers of layered nanomaterials and silicon.
• Calculation and comparison of performance parameters: sensitivity, resolution, quality factor, and evanescent field penetration depth.
• Comparative analysis against a 1DPC sensor utilizing PMMA instead of silicon.

Main Results:

• Replacing PMMA with silicon in the 1DPC structure increased the shift in resonance angle and the quality factor.
• This substitution, however, led to a decrease in sensor resolution.
• The 1DPC sensor demonstrated lower sensitivity and quality factor than conventional SPR sensors with gold films.
• The 1DPC sensor exhibited significantly higher resolution and penetration depth compared to SPR sensors.

Conclusions:

• 1DPC sensors incorporating silicon and layered nanomaterials are suitable for detecting large molecules due to their enhanced penetration depth and resolution.
• While sensitivity and quality factor may be lower than SPR, the improved resolution and penetration depth offer distinct advantages for specific biosensing applications.