SABRE (Signal Amplification By Reversible Exchange) allows for rapid, affordable and repeated hyperpolarization of molecules directly in room temperature solutions. SABRE has many applications, ranging from biomedical to high precision measurements. To achieve the full potential, we investigated key steps in spin physics, chemistry, and engineering. Specifically, we (1) engineered membrane reactors for continuous polarization, (2) we created catalytic SABRE systems for hyperpolarization of a variety of drugs and water, and investigated hyperpolarization spin physics leading us to new SABRE and PHIP modalities with intriguing field dependence, (3) we efficiently polarized and detected heteronuclei at different magnetic fields and (4) we established low-field rare spin spectroscopy displaying masing effects, ideal for ultra-high precision measurements:
(1) High SABRE polarization was obtained under continuous flow using a membrane reactor for parahydrogen dissolution. This enables a continuous stream of hyperpolarized solution for injection or to feed a high precision Zeemann MASER.
(2) We hyperpolarized popular prescription drugs (e.g. anti-tumor, fungicides and antibiotics) and amino acids. Furthermore, we hyperpolarize water and find an atypical dependence on polarization transfer field, which speaks to a novel One-H polarization transfer mechanism.
(3) We also investigate heteronuclei such as 13C, 15N and 19F at high and low fields. In this context, we use the concept of LACs (level anti crossings) to advance SABRE-SHEATH and SLIC-SABRE approaches for heteronuclear hyperpolarization. A variety of novel targets with high hyperpolarization levels and long polarization decay time constant (T1, TS) will be presented.
(4) Finally, our advances enabled the parahydrogen fueled NMR RASER (radiowave amplification by stimulated emission of radiation). The continuous hyperpolarization pumps the RASER and multimode operation allows for ultra-high precision measurements in the micro-Hz regime and beyond.
All these aspects advance the SABRE method towards important applications in various areas of science including biomedical applications and high precision measurements.