Beschreibung:
<jats:title>Abstract</jats:title><jats:p>Zinc ions play an important role in numerous crucial biological processes in the human body. The ability to image the function of Zn<jats:sup>2+</jats:sup> would be a significant asset to biomedical research for monitoring various physiopathologies dependent on its fate. To this end, we developed a novel Gd<jats:sup>3+</jats:sup> chelate that can selectively recognize Zn<jats:sup>2+</jats:sup> over other abundant endogenous metal ions and alter its paramagnetic properties. More specifically, this lanthanide chelate displayed an extraordinary increase in longitudinal relaxivity (<jats:italic>r</jats:italic><jats:sub>1</jats:sub>) of over 400 % upon interaction with Zn<jats:sup>2+</jats:sup> at 7 T and 25 °C, which is the greatest <jats:italic>r</jats:italic><jats:sub>1</jats:sub> enhancement observed for any of the metal ion‐responsive Gd‐based complexes at high magnetic field. A “turn‐on” mechanism responsible for these massive changes was confirmed through NMR and luminescence lifetime studies on a <jats:sup>13</jats:sup>C‐labeled Eu<jats:sup>3+</jats:sup> analogue. This molecular platform represents a new momentum in developing highly suitable magnetic resonance imaging contrast agents for functional molecular imaging studies of Zn<jats:sup>2+</jats:sup>.</jats:p>