A responsive europium(III) chelate that provides a direct readout of pH by MRI

J Am Chem Soc. 2010 Oct 13;132(40):14002-3. doi: 10.1021/ja106018n.


A europium(III) DO3A-tris(amide) complex is reported for imaging pH by MRI using ratiometric chemical exchange saturation transfer (CEST) principles. Deprotonation of a single phenolic proton between pH 6 and 7.6 results in an ∼5 ppm shift in the water exchange CEST peak that is easily detected by MRI. Collection of two CEST images at two slightly different activation frequencies provides a direct readout of solution pH without the need of a concentration marker.

Publication types

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

MeSH terms

  • Chelating Agents / chemistry*
  • Europium / chemistry*
  • Hydrogen-Ion Concentration*
  • Magnetic Resonance Imaging / methods*


  • Chelating Agents
  • Europium