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arXiv · 2209.05308

Using metal-organic frameworks to confine liquid samples for nanoscale NV-NMR

Kristina S. Liu·Xiaoxin Ma·Roberto Rizzato·Anna-Lisa Semrau·Alex Henning·Ian D. Sharp·Roland A. Fischer·Dominik. B. Bucher
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Abstract

Atomic-scale magnetic field sensors based on nitrogen vacancy (NV) defects in diamonds are an exciting platform for nanoscale nuclear magnetic resonance (NMR) spectroscopy. The detection of NMR signals from a few zeptoliters to single molecules or even single nuclear spins has been demonstrated using NV-centers close to the diamond surface. However, fast molecular diffusion of sample molecules in and out of nanoscale detection volumes impedes their detection and limits current experiments to solid-state or highly viscous samples. Here, we show that restricting diffusion by confinement enables nanoscale NMR spectroscopy of liquid samples. Our approach uses metal-organic frameworks (MOF) with angstrom-sized pores on a diamond chip to trap sample molecules near the NV-centers. This enables the detection of NMR signals from a liquid sample, which would not be detectable without confinement. These results set the route for nanoscale liquid-phase NMR with high spectral resolution.

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Kristina S. Liu, Xiaoxin Ma, Roberto Rizzato, Anna-Lisa Semrau, Alex Henning, Ian D. Sharp, Roland A. Fischer, Dominik. B. Bucher. 2022-09-12. Using metal-organic frameworks to confine liquid samples for nanoscale NV-NMR. https://doi.org/10.1021/acs.nanolett.2c03069

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