Halloysite Nanotube-Modified Plasmonic Interface for Highly Sensitive Refractive Index Sensing.

Area of Science:

• Nanotechnology
• Biosensing
• Surface Chemistry

Background:

• Surface Plasmon Resonance (SPR) sensors are crucial for real-time biomolecular detection.
• Existing SPR sensors often face limitations in sensitivity and require complex modifications.
• Halloysite nanotubes (HNTs) offer unique properties like large surface area and biocompatibility.

Purpose of the Study:

• To develop a novel, highly sensitive SPR sensor by modifying the plasmonic interface with HNTs.
• To investigate the effect of HNTs layer thickness on sensor performance.
• To establish an eco-friendly and cost-effective method for enhancing biosensor sensitivity.

Main Methods:

• Modification of the SPR sensor interface using a thin layer of halloysite nanotubes (HNTs).
• Tailoring the HNTs layer thickness by controlling the concentration of HNTs ethanol suspension during spraying.
• Characterization of sensor performance, including sensitivity and enhancement fold.

Main Results:

• The HNTs-modified SPR sensor demonstrated significantly improved sensitivity (10431 nm/RIU).
• Achieved a 5.6-fold enhancement in sensitivity compared to previously reported sensors.
• The HNTs layer effectively increased probing electric field intensity due to its large surface area and high refractive index.

Conclusions:

• The proposed HNTs-SPR biosensor offers a simple, biocompatible, and low-cost platform for trace-level detection.
• This chemical-free and environmentally friendly modification method enhances SPR sensor performance.
• The tailored HNTs layer enables rapid, sensitive, and nondestructive detection of biochemical species.