A water-soluble two-photon fluorescent turn-on probe for pyrophosphate anion: Design, synthesis and properties

A new water-soluble two-photon probe CuL2 for pyrophosphate anion (PPi) is designed and synthesized, and shows turn-on fluorescence with high sensitivity and selectivity. The probe CuL2 can selectively detect small amount of PPi particularly in the presence of a large excess of PO43− and ATP. The association constant of CuL2 and PPi is about 105.2, and its detection limit is 3.2 × 10−8 M. To the best of our knowledge, this is the first water-soluble two-photon fluorescent turn-on probe for PPi.