NMR Spectroscopy Techniques: Hyperpolarization for Sensitivity Enhancement

Abstract

Nuclear spin polarization can be significantly enhanced through a process called hyperpolarization, resulting in up to several orders increase of the nuclear spin polarization (compared to equilibrium thermal polarization) with concomitant gains in NMR spectroscopic and imaging signals. Here, we describe the leading techniques for NMR hyperpolarization: dynamic nuclear polarization (DNP), spin exchange optical pumping (SEOP), parahydrogen induced polarization (PHIP), and signal amplification by reversible exchange (SABRE). We also discuss key features of and schemes associated with NMR spectroscopic detection in the context of NMR hyperpolarization applications.