Thermoresponsive, spin-labeled hydrogels as separable DNP polarizing agents

Area of Science:

• Materials Science
• Biophysics
• Chemistry

Background:

• Dynamic Nuclear Polarization (DNP) enhances NMR sensitivity but is limited by short hyperpolarization lifetimes.
• Efficient separation of polarized molecules from polarizing agents (radicals) is crucial for maintaining hyperpolarization.
• Current DNP methods often face challenges in radical-induced relaxation, limiting signal enhancement.

Purpose of the Study:

• To develop novel thermoresponsive, spin-labeled hydrogels for improved DNP applications.
• To investigate the potential of thermally induced polymer network collapse for separating polarized molecules from radicals.
• To enhance the lifetime of hyperpolarization in DNP experiments.

Main Methods:

• Synthesis of thermoresponsive, spin-labeled hydrogel polymers.
• Characterization of hydrogel swelling/collapse behavior in response to temperature changes.
• Evaluation of the hydrogel's ability to separate water/polarized molecules from incorporated radicals.
• Assessment of hyperpolarization lifetimes in the presence and absence of the hydrogel system.

Main Results:

• Successfully synthesized thermoresponsive hydrogels functionalized with spin labels.
• Demonstrated thermally induced reversible collapse of the polymer network.
• Showcased efficient separation of water and other polarized molecules from radicals upon hydrogel collapse.
• Observed a significant prolongation of hyperpolarization lifetime in DNP experiments using the developed hydrogels.

Conclusions:

• Thermoresponsive, spin-labeled hydrogels offer a promising platform for advancing DNP techniques.
• The thermally triggered separation mechanism effectively mitigates radical-induced relaxation, extending hyperpolarization.
• This approach has the potential to significantly improve sensitivity and applicability of DNP in various scientific fields.