A novel 1, 8-naphthalimide compound, 4-piperidyl-9-ethylamino-{N，N-bis[ (4-piperidyl-1, 8-naphathlimide)-ethy-laminocarbonylethyl]amino}-1, 8-naphthalimide (BPNAN), was synthesized through acly-nucleophilic substitution reaction and Michael addition reaction based on 4-bromo-1, 8-naphthalic anhydride. The product was characterized by melting point, ¹H NMR and HRMS techniques. The photophysical properties were detected. The target compound exhibited strong fluorescence. BPNAN showed red shifts with increasing of the solvent polarity. pH fluorescent probe actions, metal ions and ct-DNA probes were also detected. The fluorescence intensity of BPNAN changed obviously along with pH value and can be applied as pH fluorescent probes. When the ion concentration of Cu²⁺ was 8 μmol/L, the fluorescence intensity of BPNAN enhanced to 1.2 times of the original one. When the concentration of ct-DNA was up to 500 μg/mL, the fluorescence intensity was the maximum one. In a word, BPNAN is a good kind of fluorescent materials.

Key words: 1,8-naphthalimide, solvatochromism effect, pH fluorescent probe, metal ion probe, DNA probe