Functional antibody immobilization on 3-dimensional polymeric surfaces generated by reactive ion etching.

Area of Science:

• Materials Science
• Biotechnology
• Surface Chemistry

Background:

• Antibody immobilization is crucial for biosensor development.
• Polymer substrates offer advantages for microarrays but require surface modification for optimal antibody binding.
• Fabrication techniques for creating patterned antibody surfaces are needed for high-throughput diagnostics.

Purpose of the Study:

• To develop a reactive ion etching (RIE) method for patterning antibodies on polymer substrates.
• To investigate the surface modifications induced by RIE on different polymers.
• To demonstrate the functionality of RIE-patterned antibody surfaces in immunoassays.

Main Methods:

• Reactive ion etching (RIE) using oxygen plasma to create anisotropic features on PMMA, Zeonex, and PC.
• Surface characterization using scanning electron microscopy (SEM) and contact angle measurements.
• Chemical analysis using Fourier transform infrared spectroscopy (FTIR).
• Antibody immobilization and immunoassay performance evaluation.

Main Results:

• RIE created microroughness and enhanced hydrophilicity on polymer surfaces.
• Antibodies showed preferential binding to etched areas on PMMA and Zeonex, and unetched areas on PC.
• RIE-patterned PMMA surfaces successfully captured specific antigens (cholera toxin, S. aureus enterotoxin B, B. anthracis protective antigen) in immunoassays.

Conclusions:

• RIE is a viable method for fabricating antibody microarrays on plastic substrates.
• Surface properties and antibody-substrate interactions are polymer-dependent.
• RIE-modified polymer surfaces show promise for constructing sensitive and specific biosensing platforms.