Mixed f-d coordination complexes as dual visible- and near-infrared-emitting probes for targeting DNA.

A new family of mixed-lanthanide (Yb(III) and Nd(III)) transition-metal (f-d) cyclen-Ru(II)(phen)(3) (phen = 1,10-phenanthroline) complexes were synthesized as dual visible- and near-infrared (NIR)-emitting DNA probes/sensors. Significant changes were seen in both the Ru(II) visible and the Yb(III)-centered NIR emission, which was switched off upon binding to DNA at pH 7.4. In contrast, no changes were seen in the Nd(III) emission of the analogue f-d conjugate.