The present invention provides a novel fluorescent chemosensor including a naphthalene diimide-Zn(II) complex, which can efficiently recognize pyrophosphate (PPi) at pH 7.4. The fluorescent chemosensor exhibits a new kind of excimer fluorescence, which is selective for PPi in 100% aqueous solution. Further, since the naphthalene diimide-Zn(II) complex of the present invention does not couple with inorganic phosphate (Pi) or adenosine triphosphate (ATP) and has high selectivity for PPi, it can be usefully used to detect pyrophosphate (PPi), which serves to transfer signals and store energy in living organisms.