In-situ Overhauser-enhanced nuclear magnetic resonance at less than 1 μT using an atomic magnetometer

Chemical Reaction Monitoring Using Zero-Field Nuclear Magnetic Resonance Enables Study of Heterogeneous Samples in Metal Containers

“…In high-field NMR, nuclear spins are polarized by the large magnetic field; in zero-field NMR of bulk samples, an external source of nuclear spin polarization is required. We used chemical reaction with para-enriched hydrogen gas for this demonstration; a number of alternative approaches have been shown in the context of ZULF NMR [35,61]. A closely related analogue to hydrogenative PHIP (including its heterogeneous version [62]) is signal amplification by reversible exchange (SABRE) [63][64][65], in which the hyperpolarized spin order of para-enriched hydrogen is transferred to other molecules via reversible exchange on a suitable metal-containing catalyst.…”

“…In HF NMR, nuclear spins are typically polarized prior to detection by the large magnetic field of an NMR instrument. In ZULF NMR, several alternative sample polarization modalities have been demonstrated, including sample prepolarization in an external field [26], and sample hyperpolarization [31][32][33][34][35]. Parahydrogen-induced polarization (PHIP) [36,37] is a class of hyperpolarization techniques which deliver spin polarization to a sample by way of a nuclear spin isomer of the hydrogen molecule, namely parahydrogen, characterized by zero total nuclear spin of the two hydrogen atoms.…”

Chemical Reaction Monitoring using Zero‐Field Nuclear Magnetic Resonance Enables Study of Heterogeneous Samples in Metal Containers

“…We used chemical reaction with para-enriched hydrogen gas for this demonstration;anumber of alternative approaches have been shown in the context of ZULF NMR. [36,61] Ac losely related analogue to hydrogenative PHIP (including its heterogeneous version [62] )issignal amplification by reversible exchange (SABRE), [63][64][65] in which the hyperpolarized spin order of para-enriched hydrogen is transferred to other molecules via reversible exchange on as uitable metalcontaining catalyst. Another option is to pre-polarize the molecules in an external magnetic field prior to detection.…”

Ultrasensitive Magnetic Field Sensors for Biomedical Applications

“…Novel advances in the fields of microfabrication and optical interrogation have led to significant progress in optically pumped atomic magnetometers [121][122][123][124]. The operating mechanisms of such sensors are (i) coherent population trapping [125], (ii) non-linear magneto-optical rotation [126], and (iii) spin-exchange relaxation-free [34] regimes.…”