Reusable TiN Substrate for Surface Plasmon Resonance Heterodyne Phase Interrogation Sensor.

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Surface Plasmon Resonance (SPR) is a label-free optical sensing technique.
• High-sensitivity refractive index measurements are crucial for various analytical applications.
• Titanium nitride (TiN) is explored as a substrate material for SPR sensors due to its unique properties.

Purpose of the Study:

• To develop and evaluate a TiN-based substrate for high-sensitivity refractive index measurements using SPR.
• To investigate the effect of inclined-deposited TiN (i-TiN) layers on SPR sensor performance.
• To assess the reusability and long-term durability of the TiN-based SPR substrate.

Main Methods:

• Fabrication of TiN and TiN/i-TiN nanorod array layers on glass substrates.
• Utilizing a home-built surface plasmon resonance (SPR) heterodyne phase interrogation system.
• Measuring the refractive index of a glucose solution to determine sensor performance.

Main Results:

• TiN layers achieved high bulk charge carrier densities (1.28-1.91 × 10^22 cm^-3).
• The TiN/i-TiN nanorod array exhibited a lower detection limit (6.1 × 10^-7 RIU) compared to the TiN layer (1.2 × 10^-6 RIU).
• The TiN-based substrate demonstrated high reusability and long-term durability over multiple experiments.

Conclusions:

• TiN-based substrates offer high sensitivity for refractive index measurements in SPR systems.
• The incorporation of i-TiN enhances SPR sensor performance, leading to improved detection limits.
• The developed TiN-based substrate shows significant potential for practical and reusable sensing applications.