Hyperpolarization-enhanced NMR spectroscopy with femtomole sensitivity using quantum defects in diamond

TL;DR

This paper presents a novel NMR spectroscopy method using quantum defects in diamond combined with Overhauser DNP, achieving femtomole sensitivity on dilute solutions, enabling high-resolution analysis of small molecules.

Contribution

It introduces an integrated NV-NMR and DNP technique that significantly enhances sensitivity, allowing molecular spectroscopy in dilute samples previously inaccessible.

Findings

Achieved femtomole sensitivity in NMR spectroscopy.

Enabled high-resolution analysis of dilute small molecules.

Demonstrated applications in drug discovery and single-cell studies.

Abstract

Nuclear magnetic resonance (NMR) spectroscopy is a widely used tool for chemical analysis and molecular structure identification. Because it typically relies on the weak magnetic fields produced by a small thermal nuclear spin polarization, NMR suffers from poor molecule-number sensitivity compared to other analytical techniques. Recently, a new class of NMR sensors based on optically-probed nitrogen-vacancy (NV) quantum defects in diamond have allowed molecular spectroscopy from sample volumes several orders of magnitude smaller than the most sensitive inductive detectors. To date, however, NV-NMR spectrometers have only been able to observe signals from pure, highly concentrated samples. To overcome this limitation, we introduce a technique that combines picoliter-scale NV-NMR with fully integrated Overhauser dynamic nuclear polarization (DNP) to perform high-resolution spectroscopy on a variety of small molecules in dilute solution, with femtomole sensitivity. Our technique advances mass-limited NMR spectroscopy for drug and natural product discovery, catalysis research, and single cell studies.