A new zinc (II) responsive MRI contrast agent

A new potential zinc-responsive gadolinium DO3A-based MRI contrast agent has been synthesized containing a picolinate acid group as an active arm. To study the complex properties, its emissive europium analogue has been prepared as a model. Changes in absorption and emission properties were observed as well as in the hydration number of the complex in response to increasing concentration of zinc (II). Further examination of the gadolinium complex showed a high relaxivity. In addition, a 32% modulation of relaxivity was observed in response to added zinc (II) ion which is beneficial as a zinc-responsive MRI contrast agent