Cost-efficient hyperpolarization of long-lived nuclear spin states on carbon-13 spin pairs

Current hyperpolarization methods used in preclinical research are limited by high cost (>$2M) and short hyperpolarization lifetimes (<1 min). Here we demonstrate hyperpolarization of long-lived states with inexpensive equipment. Specifically, we use parahydrogen which is simple to produce (<$10k in equipment costs) and transfer its singlet hyperpolarization by non-reactive polarization transfer to long-lived singlet states on 13C spin pairs in molecular substrates. We detail polarization transfer mechanisms and obtain hyperpolarization lifetimes in excess of two minutes. Moving forward, we expect to achieve hyperpolarization lifetimes of hours as has been demonstrated on thermally polarized 13C spin pairs.