Surface plasmon resonance sensor for domoic acid based on grafted imprinted polymer

Area of Science:

• Analytical Chemistry
• Materials Science
• Biotechnology

Background:

• Domoic acid (DA) is a potent marine neurotoxin posing significant public health risks.
• Existing detection methods often lack the sensitivity, specificity, or reusability required for rapid screening.
• Molecularly imprinted polymers (MIPs) offer a promising alternative as artificial receptors.

Purpose of the Study:

• To synthesize a molecularly imprinted polymer (MIP) film for domoic acid (DA) detection.
• To integrate the MIP film onto a gold chip for surface plasmon resonance (SPR) analysis.
• To compare the performance of the MIP-based sensor with natural antibody receptors.

Main Methods:

• Direct photo-grafting of MIP film onto a functionalized gold chip using 2-(diethylamino) ethyl methacrylate and ethylene glycol dimethacrylate.
• Surface characterization using contact angle measurements and atomic force microscopy (AFM).
• Detection of DA using a competitive binding assay on a BIAcore 3000 SPR system.

Main Results:

• A thin (40 nm), homogeneous MIP film was successfully synthesized and grafted onto the gold surface.
• The MIP sensor demonstrated sensitivity, cross-reactivity, and robustness suitable for DA detection.
• The MIP sensor showed superior reusability compared to monoclonal antibodies, enabling continuous measurement for over 2 months without performance degradation.

Conclusions:

• Surface-grafted MIPs provide a stable and reusable platform for DA detection.
• MIP-based SPR sensors offer a viable alternative to antibody-based systems for toxin monitoring.
• The developed MIP sensor demonstrates potential for long-term, continuous monitoring applications.