Probing and mapping the binding sites on streptavidin imprinted polymer surface

Area of Science:

• Polymer Science
• Biomaterials Science
• Nanotechnology

Background:

• Molecular imprinting (MIP) creates synthetic receptors on polymer surfaces.
• These receptors mimic biological recognition sites for specific molecular targets.
• Characterizing these sites at the nanoscale is crucial for understanding their function.

Purpose of the Study:

• To synthesize and characterize molecularly imprinted polymer (MIP) surfaces with specific binding sites for streptavidin.
• To utilize advanced atomic force microscopy (AFM) techniques for nanoscale analysis of these MIPs.
• To directly map streptavidin binding sites on MIP surfaces and determine binding kinetics.

Main Methods:

• Synthesis of molecularly imprinted polymer (MIP) surfaces for streptavidin.
• Atomic force microscopy (AFM) techniques, including single molecule force spectroscopy (SMFS) and recognition imaging (TREC).
• AFM measurements under physiological conditions to assess binding specificity and kinetics.

Main Results:

• SMFS revealed specific unbinding events with an unbinding force of ~300 pN for streptavidin on MIP surfaces.
• Binding probability decreased from 35.2% to 7.6% in the presence of free streptavidin, confirming specificity.
• TREC imaging mapped recognition sites with diameters of ~21 nm, corresponding to single streptavidin binding sites.

Conclusions:

• The combination of SMFS and TREC provides a powerful tool for nanoscale characterization of MIP surfaces.
• This approach enables single-molecule resolution analysis of synthetic receptors under physiological conditions.
• The findings open new avenues for developing advanced biomaterials and sensors based on MIP technology.