High-Resolution NMR Spectroscopy at Large Fields with Nitrogen Vacancy Centers

Abstract

Ensembles of nitrogen-vacancy (NV) centers are used as sensors to detect NMR signals from micron-sized samples at room temperature. In this scenario, the regime of large magnetic fields is especially interesting as it leads to a large nuclear thermal polarisation -thus, to a strong sensor response even in low concentration samples-while chemical shifts and J-couplings become more accessible. Nevertheless, this regime remains largely unexplored owing to the difficulties to couple NV-based sensors with high-frequency nuclear signals.In this work, we circumvent this problem with a method that maps the relevant energy shifts in the amplitude of an induced nuclear spin signal that is subsequently transferred to the sensor. This stage is interspersed with free-precession periods of the sample nuclear spins where the sensor does not participate. Thus, our method leads to high spectral resolutions ultimately limited by the coherence of the nuclear spin signal.

Advances in nano- and microscale NMR spectroscopy using diamond quantum sensors

“…Apply hyperpolarization methods such as Overhauser DNP, 11 PHIP, 12 dDNP, CIDNP, ... Improved NV read-out for sensitivity enhancement 149 Limited spectral resolution Increased magnetic fields (40.35 T) 10 Ultralow-field NMR in combination with hyperpolarization 150 Novel pulse sequences enabling detection at higher magnetic fields 151 In vivo conditions (medium circulation, cell movement, ...) Microfluidic devices for cell cultures such as cell traps or nano titer arrays 152,153 Sample heating (microwave and laser heating) Improved microwave resonator designs Single cell statistics Magnetic resonance imaging 73,85 allowing the parallel detection of multiple single cells Lab-on-achip Nanomol chemistry, microdroplet screening, organ-on-a-chip, point-of-care testing, drug screening, ...…”

“…Apply hyperpolarization methods such as Overhauser DNP, 11 PHIP, 12 dDNP, CIDNP, ... Improved NV read-out for sensitivity enhancement 149 Limited spectral resolution Increase magnetic fields (40.35 T) 10 Ultralow-field NMR in combination with hyperpolarization 150 Novel pulse sequences enabling detection at higher magnetic fields 151 In vivo conditions (medium circulation, cell movement, ...) Microfluidic devices for cell cultures such as cell traps or nano titer arrays 152,153 Sample heating (microwave and laser heating)…”

Advances in nano- and microscale NMR spectroscopy using diamond quantum sensors

“…Furthermore, the combination of NV-based hyperpolarization with NV-detected NMR could enable applications requiring in situ hyperpolarization like single-cell NMR or NMR of nuclei with low gyromagnetic ratios. So far, only initial proof-of-principle studies have been conducted, demonstrating that polarization from single NV centers [139][140][141] and shallow NV ensembles can be transferred to spins outside of the diamond Novel pulse sequences enabling detection at higher magnetic fields 151 In vivo conditions (medium circulation, cell movement, …) Microfluidic devices for cell cultures such as cell traps or nano titer arrays 152,153 Sample heating (Microwave & Laser heating)…”

“…Limited spectral resolutionIncrease magnetic fields (> 0.35 T)10 Ultralow-field NMR in combination with hyperpolarization 150 Novel pulse sequences enabling detection at higher magnetic fields151 In vivo conditions (medium circulation, cell movement, …) Microfluidic devices for cell cultures such as cell traps or nano titer arrays152,153 Sample heating (Microwave & Laser heating)Improved microwave resonator designsSingle cell statisticsMagnetic resonance imaging73,85 allowing the parallel detection of multiple single such as Overhauser DNP 11 , PHIP12 , dDNP, CIDNP, … Novel pulse sequences for increased readout fidelity149 Limited spectral resolution Increase magnetic fields (> 0.35 T)10 Ultralow-field NMR in combination with hyperpolarization 150…”

Advances in nano- and microscale NMR spectroscopy using diamond quantum sensors

“…Limited spectral resolutionIncrease magnetic fields (> 0.35 T)10 Ultralow-field NMR in combination with hyperpolarization 150 Novel pulse sequences enabling detection at higher magnetic fields151 In vivo conditions (medium circulation, cell movement, …) Microfluidic devices for cell cultures such as cell traps or nano titer arrays152,153 Sample heating (Microwave & Laser heating)Improved microwave resonator designsSingle cell statisticsMagnetic resonance imaging73,85 allowing the parallel detection of multiple single such as Overhauser DNP 11 , PHIP12 , dDNP, CIDNP, … Improved NV read-out for sensitivity enhancement149 Limited spectral resolution Increase magnetic fields (> 0.35 T)10 Ultralow-field NMR in combination with hyperpolarization 150…”