Plasmonic Micro-Channel Assisted Photonic Crystal Fiber Based Highly Sensitive Sensor for Multi-Analyte Detection

Area of Science:

• Photonics
• Plasmonics
• Sensor Technology

Background:

• Simultaneous detection of multiple analytes is crucial for advanced chemical and biological sensing.
• Photonic Crystal Fibers (PCFs) offer unique light-confining properties for developing novel sensor platforms.
• Surface Plasmon Resonance (SPR) is a sensitive technique for detecting changes in refractive index.

Purpose of the Study:

• To propose and numerically investigate a dual-channel PCF-based plasmonic sensor for simultaneous multi-analyte detection.
• To optimize sensor parameters for enhanced performance, including sensitivity and resolution.
• To demonstrate the sensor's capability for detecting analytes within a specific refractive index range.

Main Methods:

• Numerical investigation using the Finite Element Method (FEM) with Perfectly Matched Layer (PML) boundary conditions.
• Design of a PCF with plasmonic micro-channels on its outer surface.
• Analysis of sensor performance metrics: confinement loss, resonance coupling, resolution, sensitivity, and Figure of Merit (FOM).

Main Results:

• Achieved maximum wavelength sensitivity (WS) of 25,000 nm/RIU for channel 2 and 3000 nm/RIU for channel 1.
• Obtained maximum sensor resolution (SR) of 4.0 × 10^-6 RIU for channel 2 and 3.33 × 10^-5 RIU for channel 1.
• Demonstrated high FOM values (up to 500 RIU^-1) and low limit of detection (LOD) for both channels, with the highest reported WS for multi-analyte PCF SPR sensors.

Conclusions:

• The proposed dual-channel PCF plasmonic sensor enables simultaneous detection of multiple analytes with high sensitivity and resolution.
• The sensor is capable of detecting unknown analytes in the refractive index range of 1.32 to 1.39.
• This sensor represents a promising candidate for advanced biosensing and chemical sensing applications due to its superior performance.