pH triggered dye sensor based on pyrone unit as a donor group and furan unit as an acceptor grouphave resulted in very promising optical switches, when dye was applied by alkali-induced nucleophilic additionreaction. The dye displayedclear UV-Visible absorption changes and new fluorescence emission behaviors, which are based on intramolecular charge transfer (ICT) system of the dye molecular structure. The levels of energy potential and the electron density distributions of this dye chemosensor were also simulated and discussed using computational modelcalculation.