Multimodal Magnetic‐Resonance/Optical‐Imaging Contrast Agent Sensitive to NADH

Agents get smart: A macrocycle-based gadolinium complex undergoes an isomerization in the presence of NADH, leading to an r1 relaxivity increase of 54 %, while the intense fluorescence disappears (see scheme). This agent could facilitate the use of magnetic resonance imaging (MRI) for probing tissue redox status. Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.