A new 4-(2-N, N-dimethylamino) ethylamino-N-2-hydroxyethyl-1, 8-naphthalimide has been synthesized. The photophysical characteristics have been determined in aqueous and acetonitrile solutions. The influence of metal cations (Ni2+, Zn2+, and Cu2) and protons on the fluorescence intensity has been studied to evaluate the capacities of the newly synthesized 1, 8-naphthalimide as a fluorescence sensor. The 1, 8-naphthalimide dye has ...