An intracellular diamine oxidase triggered hyperpolarized 129Xe magnetic resonance biosensor

Abstract

Here, a novel method was developed for suppressing ¹²⁹Xe signals in cucurbit[6]uril (CB6) until the trigger is activated by a specific enzyme. Due to its noncovalent interactions with amino-groups and CB6, putrescine dihydrochloride (Put) was chosen for blocking interactions between ¹²⁹Xe and CB6. Upon adding diamine oxidase (DAO), Put was released from CB6 and a ¹²⁹Xe@CB6 Hyper-CEST signal emerged. This proposed ¹²⁹Xe biosensor was then tested in small intestinal villus epithelial cells.