Label-free detection of leptin antibody-antigen interaction by using LSPR-based optical biosensor

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Optical Physics

Background:

• Noble metal nanostructures, particularly those exhibiting localized surface plasmon resonance (LSPR), are crucial for advancing optical biosensing.
• Developing efficient and reproducible LSPR-based biosensors remains a key research objective.

Purpose of the Study:

• To fabricate a localized surface plasmon resonance (LSPR)-based label-free optical biosensor.
• To utilize a novel multi-spot gold-capped nanoparticle array (MG-NPA) biochip for enhanced biosensing capabilities.

Main Methods:

• Fabrication of MG-NPA biochip via deposition of a thin gold film on a silica nanoparticle layer.
• Immobilization of anti-leptin antibody onto the MG-NPA biochip surface.
• Detection of varying concentrations of leptin antigen (1 pg/mL-100 µg/mL) through antibody-antigen interaction.

Main Results:

• The MG-NPA biochip structure demonstrated easy excitation of LSPR signals with high reproducibility.
• The developed biosensor achieved a sensitive detection limit of 100 pg/mL for leptin antigen.
• Successful recognition of leptin antigen by the immobilized anti-leptin antibody.

Conclusions:

• The fabricated LSPR-based label-free optical biosensor employing MG-NPA biochips offers a low-cost and easily manufacturable solution.
• The biosensor utilizes a simple optical system and shows potential for broad application in immunoassays with similar antibody-antigen models.