A novel blue-emitting 1,8-naphthalimide fluorophore designed as a molecular PET-based probe for determination of pH and detection of transition metal ions in the environment was successfully synthesized. Novel compound was configured on the "fluorophore-spacer-receptor" format. Due to the tertiary amine receptor the novel system showed "off-on" switching properties under the transition from alkaline to acid media (FE = 3.2) and in the presence of Zn(2+) ions (FE = 2.5). The results obtained illustrate the high potential of the synthesized blue-emitting 1,8-naphthalimide fluorophore as an efficient pH chemosensing material and a selective probe for Zn(2+) ions.