Reusable optical bioassay platform with permeability-controlled hydrogel pads for selective saccharide detection

Area of Science:

• Biotechnology
• Materials Science
• Analytical Chemistry

Background:

• Developing reusable and selective bioassay platforms is crucial for efficient diagnostics.
• Existing methods often face challenges with reagent stability and analyte specificity.
• Hydrogel-based systems offer potential for controlled molecular transport and analyte capture.

Purpose of the Study:

• To develop a reusable optical bioassay platform for selective saccharide detection.
• To engineer permeability-controlled hydrogel pads using Layer-by-Layer (LbL) self-assembly.
• To integrate a fluorescence resonance energy transfer (FRET) based glucose assay within the hydrogel system.

Main Methods:

• Fabrication of hemispherical hydrogel pads entrapping dye-labeled dextran and Concanavalin A (ConA).
• Surface coating of hydrogel pads with polyelectrolyte multilayers via LbL self-assembly to control permeability.
• Incorporation of a FRET-based optical assay for glucose detection.
• Evaluation of encapsulation efficiency, analyte diffusion, and assay reusability.

Main Results:

• Achieved 75% encapsulation efficiency of the ConA/Dextran complex with minimal leakage.
• Demonstrated selective permeability, allowing detection of monosaccharides (glucose) and disaccharides (sucrose) while excluding polysaccharides (dextran).
• Obtained a linear glucose calibration curve from 0 to 10mM.
• Showcased high signal reproducibility (>90%) upon regeneration, confirming platform reusability.

Conclusions:

• The developed LbL-coated hydrogel pads provide a selective and reusable platform for optical saccharide detection.
• The permeability control mechanism effectively immobilizes sensing elements while allowing target analyte diffusion.
• This reagentless bioassay platform shows significant promise for sensitive and specific glucose monitoring.