The main challenge for designing fluorescence sensors for negatively charged species is that its hydration tendency reduces the sensors' ability to interact with the target analyte. One potential solution to surmount this challenge involves the employment of a displacement strategy, where initially the fluorescent probe is complexed to a metal ion that quenches the fluorescence (metal-ion-induced fluorescence quenching). Then, decomplexation of the metal ion by the negatively charged analyte leads to a restored ESIPT fluorophore. Copper complexes have been used for Pi and PPi sensing, 25 however no other condensed phosphate chains have been examined with related complexes.