Yang Wang (Very High Field NMR Center of Lyon (CRMN Lyon), France)
LinkedIn: @Yang Wang; X: @WangYan35529716; Bluesky: @yangwangcz.bsky.social
Abstract: Hyperpolarization techniques can boost NMR sensitivity by over 10,000-fold [1]. Among these, dissolution dynamic nuclear polarization (dDNP) is well established but suffers major drawbacks: it is destructive, single-use, and results in dilution upon sample dissolution, leading to rapid signal decay and incompatibility with multi-scan NMR experiments [2].
We are developing a benchtop DNP platform designed to enable replenishable hyperpolarization without dilution. This approach uses hyperpolarizing materials (HYPOPs) [3] within a compact benchtop polarizer [4], coupled directly to a benchtop NMR spectrometer for solution-state detection. Our long-term goal is a closed-loop system allowing repeated freeze-DNP-melt-flow cycles.
A critical challenge is maintaining polarization during the melt. In our current system, the sample is transferred from a 77 K DNP cryostat inside a 1 T benchtop polarizer into a dedicated melting station. This first prototype uses a guided high-flux (500 L/min), high-temperature (630 °C) air stream to melt a 250 µL sample in 5 seconds.
We are now working to reduce the melt time below 1 second by increasing airflow, temperature, and integrating high-power laser light. Ultimately, we aim to couple this rapid melt setup with DNP and solution-state hyperpolarized NMR for multi-scan acquisition capability.
References:
[1] Ardenkjær-Larsen, J. H., et al. PNAS 100.18 (2003): 10158-10163.
[2] Golman, K., et al. Cancer Res. 66.22 (2006): 10855-10860.
[3] El Daraï, T., Cousin, S.F., Stern, Q., et al. Nat. Commun. 12 (2021): 4695.
[4] Bocquelet, C., et al. Sci. Adv. 10 (2024): eadq3780.
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Hi Yang! Thank you for the presentation.
I was wondering if you observe any noticeable time lag associated with activating the heat gun during the melting process? If so, have you considered alternative heating methods, such as infrared or laser-based systems that might allow for a more rapid and controlled melt?
Regarding the freeze-melt and then flow cycles, how reproducible are your polarization levels across repeated runs?
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Hi Kshama,
Thank you for your questions !
Indeed, the heat gun does require a few seconds after activation to reach the target temperature. To address this, I preheat the gun to the desired temperature before exposing the sample, so that the hot air is already at the setpoint at the very start of the melting process.
I have also considered three alternative heating strategies. Among them, infrared laser heating is particularly promising. We have recently acquired a 1 kW, 1 μm wavelength IR laser system, which is currently being installed. I hope to begin testing it in the coming months and are looking forward to sharing new results with you.
In parallel, we are also simulating microwave heating approaches, although the heating speed appears to be limited in this case…
Regarding your question on reproducibility, we unfortunately do not yet have experimental data. However, we are planning a series of repeated melt-DNP experiments in the coming months to verify the polarization reproducibility across cycles.
Best regards,
Yang-
Sounds great Yang! All the best and thank you!
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