Gradient hydrogel matrix for microarray and biosensor applications: an imaging SPR study.

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Biosensor Technology

Background:

• Developing advanced biosensor matrices is crucial for sensitive and selective biomolecular detection.
• Poly(ethylene glycol) methacrylate and 2-hydroxyethyl methacrylate hydrogels offer tunable properties for biosensing applications.

Purpose of the Study:

• To create and characterize a gradient biosensor matrix for efficient screening of hydrogel properties.
• To evaluate the size-selectivity of the hydrogel matrix for different biomolecules.
• To optimize biosensor performance using imaging surface plasmon resonance (iSPR).

Main Methods:

• Fabrication of a gradient hydrogel matrix using UV-initiated graft copolymerization with controlled exposure times.
• Utilizing imaging surface plasmon resonance (iSPR) in wavelength interrogation mode for high-resolution analysis.
• Assessing matrix performance through immobilization of human serum albumin and interaction studies with its antibody and fibrinogen.
• Investigating size selectivity using a synthetic polypeptide and calmodulin interaction pair.

Main Results:

• Generated a gradient matrix with physical thicknesses from nanometers to tens of nanometers.
• Demonstrated excellent properties for rapid evaluation and screening of hydrogel performance.
• Observed very low nonspecific binding with mixed hydrogel matrices.
• Confirmed size-selective diffusion and interaction, with smaller molecules freely diffusing and larger proteins being hindered.

Conclusions:

• The gradient hydrogel matrix is highly effective for optimizing biosensor performance and screening hydrogel compositions.
• The observed size selectivity is attributed to UV-initiated cross-linking and protein-mediated attachment.
• This approach facilitates the development of more specific and sensitive biosensing platforms.