Highly sensitive fluorescence probe based on chitosan nanoparticle for selective detection of Hg2+ in water

► A novel fluorescence chemosensor (DA-CN) was prepared to detect Hg2+ in aqueous solution. ► DA-CN based on chitosan nanoparticle as support and dansylamide as fluorescent center. ► This sensing material had excellent dispersibility and stability in water. ► It could rapidly recognize Hg2+ over other metal ions within a broad pH span. ► This material gave potential application in biosensors, toxicology and environmental science.