The paper reports on the synthesis and fluorescence characteristics of novel 1,8-naphthalimide fluorophore. It was configured as a “fluorophore-spacerreceptor” system able to act as a pH-probe via PET (photoinduced electron transfer) fluorescence sensing mechanism. Due to the tertiary amine receptor the novel probe showed “off-on” switching properties under the transition from alkaline to acid media. Also, the ability of the probe to detect metal ions in water/ dimethylformamide (1:1, v/v) has been evaluated by monitoring the changes of its fluorescence intensity. Among the tested metal ions (Cu2+, Pb2+, Zn2+, Ni2+, Hg2+, Fe3+) only the presence of Fe3+ was efficiently detected by fluorescence quenching mechanism.
