Europium(III) DOTA-tetraamide complexes as redox-active MRI sensors

J Am Chem Soc. 2012 Apr 4;134(13):5798-800. doi: 10.1021/ja211601k. Epub 2012 Mar 23.


PARACEST redox sensors containing the NAD(+)/NADH mimic N-methylquinolinium moiety as a redox-active functional group have been designed and synthesized. The Eu(3+) complex with two quinolinium moieties was nearly completely CEST-silent in the oxidized form but was "turned on" upon reduction with β-NADH. The CEST effect of the Eu(3+) complex containing only one quinolinium group was much less redox-responsive but showed an unexpected sensitivity to pH in the physiologically relevant pH range.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amides / chemistry*
  • Europium / chemistry*
  • Heterocyclic Compounds, 1-Ring / chemistry*
  • Hydrogen-Ion Concentration
  • Magnetic Resonance Imaging / methods*
  • Organometallic Compounds / chemical synthesis
  • Organometallic Compounds / chemistry*
  • Oxidation-Reduction


  • Amides
  • Heterocyclic Compounds, 1-Ring
  • Organometallic Compounds
  • 1,4,7,10-tetraazacyclododecane- 1,4,7,10-tetraacetic acid
  • Europium