A Highly Selective Pyrophosphate Sensor Based on ESIPT Turn-On in Water

Pyrophosphate (PPi) is a biologically important target. A binuclear system 3 circle 2Zn is found to selectively recognize PPi, leading to a ratiometric fluorescent sensor at pH 7.4 in water. The binding event triggered a large fluorescence response (similar to 100 nm bathochromic shift) by turning on the excited state intramolecular proton transfer (ESIPT). Detection of PPi released from a PCR experiment indicated that this new probe could be a useful tool in bioanalytical applications.