Analysis of immunoreaction with localized surface plasmon resonance biosensor

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Optical Sensing

Background:

• Localized surface plasmon resonance (LSPR) biosensors offer label-free detection capabilities.
• Gold colloids on glass substrates are commonly employed in LSPR sensor design.
• Self-assembled monolayers (SAMs) facilitate the immobilization of gold nanoparticles.

Purpose of the Study:

• To develop and evaluate a novel LSPR-based optical biosensor for the label-free detection of human immunoglobulin G (IgG).
• To demonstrate a simplified approach for fabricating LSPR sensors using readily available materials and techniques.

Main Methods:

• Fabrication of an LSPR biosensor by chemically hydroxylating a glass substrate.
• Immobilization of gold colloids onto the substrate via electrostatic adsorption.
• Characterization of LSPR spectra using UV-vis absorption spectroscopy.
• Assessment of sensor specificity through rigorous nonspecific binding tests.

Main Results:

• The LSPR sensor demonstrated sensitivity to changes in the local dielectric environment upon analyte binding.
• Absorbance changes correlated with the concentration of human IgG, indicating successful detection.
• The sensor exhibited specificity, validated by extensive nonspecific binding assays.
• LSPR sensing provided results comparable to Surface Plasmon Resonance (SPR) techniques.

Conclusions:

• The developed LSPR biosensor enables sensitive and specific label-free detection of human IgG.
• The fabrication method is straightforward, utilizing chemical hydroxylation and electrostatic adsorption.
• LSPR sensing presents a simplified and cost-effective alternative to traditional SPR methods for immunoreaction detection.