Novel renewable immunosensors based on temperature-sensitive PNIPAAm bioconjugates

Area of Science:

• Biomaterials Science
• Immunosensor Technology
• Surface Chemistry

Background:

• Traditional immunosensors often face challenges with regeneration and reusability.
• Developing efficient methods for antibody immobilization and antigen dissociation is crucial for sensor longevity.
• Temperature-responsive polymers offer unique stimuli-responsive properties for biomolecule conjugation.

Purpose of the Study:

• To create a novel renewable immunosensor utilizing a temperature-controlled surface.
• To demonstrate the reversible binding and release of antigens using antibody-polymer conjugates.
• To evaluate the performance and reusability of the developed immunosensor system.

Main Methods:

• Conjugation of antibodies (anti-BSA) to temperature-responsive poly(n-isopropylacrylamide) (PNIPAAm).
• Utilizing the low critical solution temperature (LCST) phase transition of PNIPAAm for controlled conformation and bioaffinity changes.
• Monitoring binding and dissociation using Quartz Crystal Microbalance (QCM), confocal fluorescence, native electrophoresis, laser-induced fluorescence, and electrochemical impedance.

Main Results:

• The PNIPAAm-antibody conjugate exhibited controllable conformation changes with temperature, altering bioaffinity for the target antigen (BSA).
• A renewable anti-BSA surface was successfully generated, allowing for repeated antigen binding.
• The immunosensor demonstrated high reusability, retaining activity and specificity for over 30 reproducible assays with an 89% dissociation rate.

Conclusions:

• A novel temperature-controlled renewable immunosensor platform was successfully developed.
• The use of thermoresponsive PNIPAAm-antibody conjugates provides an efficient and easy-to-handle method for immunosensor regeneration.
• This approach offers a promising strategy for developing durable and reusable biosensing devices.