A smart T1-weighted MRI contrast agent for uranyl cations based on a DNAzyme-gadolinium conjugate.

The Analyst

PubMedID: 24005082

Xu W, Xing H, Lu Y. A smart T1-weighted MRI contrast agent for uranyl cations based on a DNAzyme-gadolinium conjugate. Analyst. 2013;.
Rational design of smart MRI contrast agents with high specificity for metal ions remains a challenge. Here, we report a general strategy for the design of smart MRI contrast agents for detecting metal ions based on conjugation of a DNAzyme with a gadolinium complex. The 39E DNAzyme, which has high selectivity for UO2(2+), was conjugated to Gd(iii)-DOTA and streptavidin. The binding of UO2(2+) to its 39E DNAzyme resulted in the dissociation of Gd(iii)-DOTA from the large streptavidin, leading to a decrease of the T1 correlation time, and a change in the MRI signal.