Slab waveguide-based particle plasmon resonance optofluidic biosensor for rapid and label-free detection

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Optical Sensing

Background:

• Effective bio-sensing platforms are crucial for translating research to clinical applications, but simultaneous rapid and sensitive detection remains a challenge.
• Existing biosensors often face limitations in speed, sensitivity, or cost-effectiveness for practical biomedical use.

Purpose of the Study:

• To develop and demonstrate a novel, cost-effective, label-free, real-time, and sensitive biosensor for practical clinical applications.
• To leverage waveguide-based particle plasmon resonance (WGPPR) with gold nanoparticles (AuNPs) for enhanced optical detection.

Main Methods:

• Fabrication of a suspended glass slab waveguide with excellent optical confinement.
• Deposition of gold nanoparticles (AuNPs) on the waveguide surface to utilize the localized surface plasmon resonance (LSPR) effect.
• Detection of refractive index changes and biochemical analytes (IgG) by monitoring transmitted light intensity.

Main Results:

• The WGPPR biosensor demonstrated a sensor resolution of 1.43 × 10^-4 RIU, a 395% enhancement over sensors without AuNPs.
• Achieved a detection limit (LOD) of 614 ng mL^-1 for IgG in approximately 4 minutes.
• Validated the bio-detection sensing functionality and real-time detection capabilities.

Conclusions:

• The developed WGPPR biosensor offers a unique combination of simple structure, high sensitivity, and rapid bio-sensing.
• This technology is suitable for practical biomedical sensing applications and meets point-of-care (POC) requirements.
• The study presents a promising advancement in label-free biosensing for clinical diagnostics.