Highly sensitive graphene biosensors based on surface plasmon resonance.

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Materials Science

Background:

• Surface Plasmon Resonance (SPR) biosensors are crucial for label-free biomolecular detection.
• Conventional SPR sensors often face limitations in sensitivity and detection limits.
• Graphene's unique properties offer potential for enhancing biosensor performance.

Purpose of the Study:

• To present a novel SPR biosensor design incorporating a graphene layer on a gold thin film.
• To theoretically evaluate the sensitivity enhancement of the proposed graphene-SPR biosensor compared to traditional gold SPR sensors.
• To investigate the contribution of graphene's optical properties and biomolecule adsorption to the enhanced sensitivity.

Main Methods:

• Utilizing the Attenuated Total Reflection (ATR) method for refractive index change detection.
• Modeling and calculation of SPR performance for a graphene-on-gold layered structure.
• Comparing the sensitivity of the graphene-SPR biosensor with varying numbers of graphene layers (L) to a conventional gold SPR biosensor.

Main Results:

• The proposed graphene-on-gold SPR biosensor demonstrates a sensitivity increase by a factor of (1 + 0.025 L) x gamma, where gamma > 1.
• The enhanced sensitivity is attributed to both increased biomolecule adsorption on graphene (factor gamma) and graphene's inherent optical properties.
• The sensitivity improvement is directly proportional to the number of graphene layers (L) incorporated into the sensor.

Conclusions:

• The integration of graphene with gold thin films in an SPR biosensor architecture significantly boosts sensor sensitivity.
• This graphene-SPR biosensor design offers a promising platform for more sensitive and efficient detection of biomolecules.
• The findings highlight the potential of graphene-based nanomaterials in advancing biosensing technologies.