Lanthanide complexes as redox and ROS/RNS probes: A new paradigm that makes use of redox-reactive and redox non-innocent ligands

Lanthanides complexes are indispensable in fields related to medicine and biology. Their success lies the great number of unpaired electrons (4f7 configuration Gd3+ ion) that makes them ideal contrasts agents for magnetic resonance imaging. On other hand their narrow emission bands long lifetime excited state provide unique luminescence properties. The aqueous solution chemistry lanthanides is dominated by (+III) oxidation under oxygenated atmosphere. This severely limits use as redox probes, not surprisingly very few redox-switches employing lanthanide ions were reported until 2010. A promising approach based on redox-reactive non-innocent ligands has recently emerged literature, which overcomes this limitation expands application monitoring. Herein ligand acts a redox-sensor either changing its or reacting with reactive oxygen (or nitrogen) species (ROS/RNS). Its response induces changes environment ion, reporter status. detection modification optical properties complexes, conventional spectroscopic techniques. We summarize review article recent advances burgeoning field, special emphasis biological relevant ROS, RNS