In vivo magnetic resonance imaging of glucose via interfacial enzyme-catalyzed signal-amplifying probes

Visualizing dynamic glucose metabolism is critical for precision medicine, yet existing magnetic resonance imaging (MRI) techniques lack specificity and sensitivity. Here, we developed Cu 2 Se@GOx, a glucose oxidase (GOx)-encapsulated diamagnetic Cu 2 Se probe, for in vivo tumor glucose imaging. GOx catalyzes glucose oxidation to generate hydrogen peroxide, which oxidizes Cu⁺ at the interface of Cu 2 Se and GOx to paramagnetic Cu 2+ . This enzyme-catalyzed switch amplifies T 1 -weighted MRI signals by over 12.6-fold with high specificity, avoiding interference from endogenous metabolites. In this proof-of-concept study, Cu 2 Se@GOx successfully distinguishes glucose heterogeneity between 4T1 and L929 cell-inoculated mice. Further, it monitors therapeutic responses to GLUT1 inhibitors (BAY-876) and chemotherapy (doxorubicin), where reduced signals correlate with suppressed glucose uptake and GLUT1 expression. Post-imaging assessments revealed no major organ damage, confirming good biocompatibility. By translating enzymatic catalysis into quantifiable contrast, this radiation-free platform offers a promising non-invasive tool for precise tumor diagnosis and metabolic profiling.