High-Resolution Nuclear Magnetic Resonance Spectroscopy with Picomole Sensitivity by Hyperpolarization on a Chip
| Autor: | Malcolm H. Levitt, William J. Hale, Marcel Utz, Matheus Rossetto, James Eills, Manvendra Sharma |
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| Rok vydání: | 2019 |
| Předmět: |
Chemical Physics (physics.chem-ph)
Analyte Chemistry FOS: Physical sciences food and beverages High resolution Physics - Applied Physics Applied Physics (physics.app-ph) General Chemistry Nuclear magnetic resonance spectroscopy 010402 general chemistry Chip 01 natural sciences Biochemistry Catalysis 3. Good health 0104 chemical sciences Colloid and Surface Chemistry Nuclear magnetic resonance Physics - Chemical Physics Hyperpolarization (physics) |
| Zdroj: | Journal of the American Chemical Society. 141(25) |
| ISSN: | 1520-5126 |
| Popis: | We show that high-resolution NMR can reach picomole sensitivity for micromolar concentrations of analyte by combining parahydrogen induced hyperpolarisation (PHIP)with a high-sensitivity transmission line micro-detector. The para-enriched hydrogen gas is introduced into solution by diffusion through a membrane integrated into a microfluidic chip. NMR microdetectors, operating with sample volumes of a few $\mu$L or less, benefit from a favourable scaling of mass sensitivity. However, the small volumes make it very difficult to detect species present at less than millimolar concentrations in microfluidic NMR systems. In view of overcoming this limitation, we implement parahydrogen-induced polarisation (PHIP) on a microfluidic device with 2.5~$\mathrm{\mu L}$ detection volume. Integrating the hydrogenation reaction into the chip minimises polarisation losses to spin-lattice relaxation, allowing the detection of picomoles of substance. This corresponds to a concentration limit of detection of better than $\mathrm{1\,\mu M\,\sqrt{s}}$, unprecedented at this sample volume. The stability and sensitivity of the system allows quantitative characterisation of the signal dependence on flow rates and other reaction parameters and permits homo- and heteronuclear 2D NMR experiments at natural $^{13}\mathrm{C}$ abundance. Comment: 27 pages, 8 figures |
| Databáze: | OpenAIRE |
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