Ratiometric fluorescence recognition for pyrophosphate on the basis of terpyridine derivative

Diphosphate (pyrophosphate, PPi) is vital for organisms, and therefore its detection is of special importance. In this paper, one cadmium complex of terpyridine (tpy) derivative, 4'-(aminomethylphenyl)-2,2':6',2"-terpyridine (aptpy), has been reported for the ratiometric fluorescence recognition of PPi. When added with cadmium, the emission of aptpy at 358 nm was greatly enhanced and red shifted to 397 nm due to the complexation-induced ICT process, which then blue shifted to 349 nm upon the further addition of PPi. Based on the different response of dual fluorescence emissions at 349 and 397 nm, a ratiometric fluorescence method could be successfully established for the fluorescence recognition of PPi. With that, PPi could be successfully discriminated from other structurally similar anions, including nucleotide triphosphates.