Dual-channel differential surface plasmon ellipsometry for bio-chemical sensing

Area of Science:

• Nanotechnology and Surface Science
• Biomedical Engineering
• Analytical Chemistry

Background:

• Surface plasmon resonance (SPR) is a powerful label-free technique for detecting molecular interactions.
• Existing SPR systems often face challenges with common-mode noise and limited multiplexing capabilities.
• Differential surface plasmon ellipsometry (DSPE) offers a potential solution for enhanced sensitivity and multiplexing.

Purpose of the Study:

• To demonstrate a dual-channel SPR sensing device utilizing the DSPE method.
• To evaluate the device's performance in noise reduction, linearity, and comparative biomolecular detection.
• To showcase the potential of DSPE for multi-analyte sensing applications.

Main Methods:

• Development and implementation of a dual-channel SPR sensing device based on DSPE.
• Experimental validation of common-mode noise removal through differential measurements.
• Assessment of linearity against refractive index changes and a protein-antibody binding assay.
• Comparison with a commercial SPR instrument (Nomadics SensiQ Discovery).

Main Results:

• Successful demonstration of common-mode noise removal in the DSPE system.
• Linear response observed with changes in refractive index, indicating reliable sensing.
• Protein-antibody binding study showed comparable performance to a commercial SPR instrument.
• First multi-channel sensing results using DSPE presented, highlighting its multiplexing potential.

Conclusions:

• The DSPE method enables effective common-mode noise subtraction in dual-channel SPR sensors.
• The developed device exhibits linear response and is suitable for sensitive biomolecular detection.
• DSPE offers a promising platform for developing cost-effective, highly multiplexed biosensing systems.