A microwell array structured surface plasmon resonance imaging gold chip for high-performance label-free immunoassay

Area of Science:

• Biophotonics
• Biosensing
• Surface Chemistry

Background:

• Surface Plasmon Resonance Imaging (SPRi) is valuable for label-free biomolecular studies but faces limitations in sensitivity and image contrast.
• Conventional gold chips for SPRi lack the necessary features for enhanced signal detection and clear imaging.
• Developing improved SPRi platforms is crucial for advancing high-throughput diagnostic and analytical applications.

Purpose of the Study:

• To develop a high-performance SPRi chip with enhanced sensitivity and image quality.
• To create a patterned microwell array on a gold chip for improved biomolecular detection.
• To demonstrate the utility of the novel chip in label-free immunoassay applications.

Main Methods:

• Fabrication of a patterned microwell array on a gold chip using photolithography of polydopamine (PDA) thin film.
• Construction of region-defined sensing arrays on the modified gold chip surface.
• Evaluation of immunoassay performance using anti-ochratoxin A (anti-OTA) monoclonal antibody detection.

Main Results:

• The microwell array SPRi chip demonstrated a 18%-32% increase in signal intensity compared to conventional gold chips.
• Enhanced intrinsic sensitivity was achieved due to intensified surface plasmon waves within the microwells.
• High-contrast SPRi images with well-defined sensing areas were obtained, facilitating signal analysis and background suppression.

Conclusions:

• The novel microwell array SPRi chip significantly enhances detection sensitivity and image quality for label-free assays.
• This technology offers a promising platform for high-throughput, quantitative analysis of biomolecular interactions.
• The developed chip design addresses key limitations of conventional SPRi, paving the way for improved biosensing applications.