Simple surface modification techniques for immobilization of biomolecules on SU-8

Area of Science:

• Materials Science
• Biotechnology
• Surface Chemistry

Background:

• SU-8, an epoxy-based negative photoresist, is widely used in microfabrication for biosensors.
• Effective immobilization of bioreceptors onto SU-8 surfaces is crucial for biosensor functionality.
• Surface modification techniques are needed to introduce functional groups for bioreceptor attachment.

Purpose of the Study:

• To investigate simple chemical treatments for modifying SU-8 surfaces.
• To compare the efficacy of glycine and 11-mercapto undecanoic acid as crosslinkers for SU-8 functionalization.
• To determine the optimal surface chemistry for immobilizing Human Immunoglobin G (HIgG) for biosensor applications.

Main Methods:

• Chemical treatments involving acid/alkali to generate hydroxyl groups on SU-8.
• Grafting of functional groups using glycine and 11-mercapto undecanoic acid as crosslinkers.
• Covalent immobilization of HIgG to SU-8 via carbodiimide/succinimide chemistry.
• Verification of immobilized HIgG activity using fluorescence imaging with FITC-tagged antibodies.

Main Results:

• Successful grafting of functional groups onto SU-8 surfaces was achieved through chemical treatments.
• Both glycine and 11-mercapto undecanoic acid facilitated surface modification.
• Carbodiimide/succinimide chemistry enabled covalent immobilization of HIgG.
• Fluorescence imaging confirmed the activity of immobilized HIgG, indicating successful functionalization.

Conclusions:

• Simple chemical treatments can effectively modify SU-8 surfaces for biosensor applications.
• The choice of crosslinker impacts the functionalization of SU-8 surfaces.
• The developed method allows for the immobilization of active bioreceptors, paving the way for advanced biosensor development.