A New Reactive 1,8-Naphthalimide Derivative for Highly Selective and Sensitive Detection of Hg2.

A 1,8-naphthalimide derivative with a reactive aliphatic hydroxyl was designed and synthesized as a fluorescent probe. Its structure was characterized by IR, 1H NMR, 13C NMR, LC-MS and HPLC. The probe showed high selectivity and sensitivity to Hg2+ over other metal ions such as Pb2+, Na+, K+, Cd2+, Cr3+, Zn2+, Cu2+, Ni2+, Ca2+, Fe3+, Fe2+, Co2+, Mn2+ and Mg2+ in MeCN/H2O (15/85, v/v). The increase in fluorescence intensity was linearly proportional to the concentration of Hg2+ in the range of 18-40 μM with a detection limit of 1.38 × 10-7 mol/L. The probe could work in a pH span of 4.3-9.0 and respond to Hg2+ quickly with strong anti-interference ability. Job's plot suggested a 1:2 complex of the probe and Hg2+.