pyridine (SPHN) as the coordinated ligand has been synthesized for the selective recognition of pyrophosphate (PPi) over other anions including phosphate in a mixed aqueous solution. The fluorescence enhancement of SPHN in association with Zn2+ ions is quenched in the presence of intracellular pyrophosphate. This phenomenon is utilized in the construction of a logic gate. The binding of SPHN with Zn2+