A Highly Selective and Sensitive Fluorescent Chemosensor for Hg ²⁺ in Neutral Buffer Aqueous Solution

A selective and sensitive fluorescent chemosensor for Hg²⁺, which was composed of two aminonaphthalimide fluorophores and a receptor of 2,6-bis(aminomethyl)pyridine, was synthesized through the reaction of 2,6-bis(chloromethyl)pyridine and N-[2-(2-hydroxyethoxy)ethyl]-4-piperazino-1,8-naphthalimide. The chemosensor showed an about 17-fold increase in fluorescence quantum yield upon addition of 1 equiv of Hg²⁺ in neutral buffer aqueous solution, and the other common metal ions did not notably disturb the detection of Hg²⁺.