title: Design of a15N Molecular Unit to Achieve Long Retention of Hyperpolarized Spin State.
abstract: Nuclear hyperpolarization is a phenomenon that can be used to improve the sensitivity of magnetic resonance molecular sensors. However, such sensors typically suffer from short hyperpolarization lifetime. Herein we report that [15N, D14]trimethylphenylammonium (TMPA) has a remarkably long spin-lattice relaxation time (1128 s, 14.1 T, 30 °C, D2O) on its15N nuclei and achieves a long retention of the hyperpolarized state. [15N, D14]TMPA-based hyperpolarized sensor for carboxylesterase allowed the highly sensitive analysis of enzymatic reaction by15N NMR for over 40 min in phophate-buffered saline (H2O, pH 7.4, 37 °C).
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nonaka
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Hirano
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Imakura
authors.affiliation: Incubation Center for Advanced Medical Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Takakusagi
authors.affiliation: Incubation Center for Advanced Medical Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.|Innovation Center for Medical Redox Navigation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Ichikawa
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Sando