Zwitterionic polymer-based platform with two-layer architecture for ultra low fouling and high protein loading

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Analytical Chemistry

Background:

• Traditional surface coatings face a trade-off between resistance to nonspecific adsorption and binding capacity.
• Developing materials that overcome this limitation is crucial for advanced biosensor applications.

Purpose of the Study:

• To engineer a "two-layer" zwitterionic polycarboxybetaine acrylamide (pCB) binding platform.
• To achieve both ultra-low fouling and high protein loading properties simultaneously.

Main Methods:

• Fabrication of a pCB platform with distinct first (high packing density, water-free) and second (low packing density) layers.
• Tuning polymer properties via tetraethylthiuram disulfide (TED) and water content.
• In situ modification with antihuman thyroid stimulating hormone (TSH) IgG and TSH antigen detection.
• Testing nonfouling properties using undiluted blood plasma.
• Surface plasmon resonance (SPR) sensing for monitoring interactions.

Main Results:

• The two-layer pCB structure effectively minimized nonspecific adsorption from complex media.
• High protein immobilization and antigen detection capabilities were demonstrated.
• The platform exhibited excellent nonfouling properties when exposed to undiluted blood plasma.

Conclusions:

• The developed "two-layer" pCB binding platform successfully overcomes the typical trade-off between fouling resistance and binding capacity.
• This platform shows significant promise for enhancing the performance of biosensors, particularly in complex biological samples.