Effect of surface parameters on the performance of IgG-arrayed hydrogel chips: a comprehensive study

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Immunodiagnostics

Background:

• 3D polyurethane (PU) hydrogels are utilized in direct immunoassays.
• Understanding hydrogel surface properties is crucial for optimizing assay performance.
• Standard commercial chip surfaces serve as benchmarks for comparison.

Purpose of the Study:

• To correlate the assay performance of 3D PU hydrogel surfaces with various physical surface parameters.
• To investigate the impact of modifications (cross-linkers, additives) on hydrogel immunoassay sensitivity.
• To compare the performance of modified hydrogels against commercial reference surfaces.

Main Methods:

• Direct immunoassay for immunoglobulin G (IgG) on 3D PU hydrogel surfaces.
• Characterization of surface parameters: water content, expansion, mechanical stability, hydrophilicity, thickness, and topography.
• Comparative analysis with commercial chip surfaces (ARChip Epoxy, Nexterion slide H, HydroGel).

Main Results:

• A strong correlation between assay sensitivity and physical surface parameters was observed for hydrogels of the same chemical composition.
• Assay sensitivity increased with decreasing hydrogel concentration, roughness, water content, and expansion.
• Hydrophobic layers with low water content demonstrated higher measurement reproducibility across all tested hydrogels.

Conclusions:

• Physical surface properties significantly influence the assay performance of 3D PU hydrogels in direct immunoassays.
• Tailoring hydrogel concentration and surface characteristics can enhance immunoassay sensitivity and reproducibility.
• The findings provide insights for designing advanced hydrogel-based diagnostic platforms.