A novel, potential dye chemosensor based on pyrrole as a donor unit and isophorone as an acceptor unit have caused sizeable optical changes when used as a reversible, pH-induced, molecular switching in the presence of alkali/acid stimulus. The dye also exhibited marked UV-visible absorption changes and highly fluorescence quenching in the presence of fluoride anions, which are based on intramolecular charge transfer (ICT) system. The level of energy potential and the electron flowing stream of this dye chemosensor such as HOMO and LUMO values were calculated by computational calculation approaches.