Tuning macrocycles to design ‘turn-on’ fluorescence probes for manganese( ii ) sensing in live cells

We tune the coordination environment of macrocyclic ligands to design two novel fluorescence sensors for Mn(2+). The BODIPY-based Mn(2+) sensor M1 affords an excellent, 52 fold, fluorescence 'turn-on' response despite the paramagnetic nature of Mn(2+). The lipophilic probe is cell-permeable and confocal imaging demonstrates that the sensor distinctly detects Mn(2+) within live cells.