An efficient chitosan-naphthalimide fluorescent probe for simultaneous detection and adsorption of Hg2+ and its application in seafood, water and soil environments

As a virulent heavy metal ion, Hg 2+ will lead to a serious threat to ecosystem and human health. In this work, we reported a chitosan-naphthalimide fluorescent probe CS-NA-ITC for specific recognition and efficient adsorption of Hg 2+ . CS-NA-ITC showed no fluorescence in solution state, while the fluorescence intensity increased obviously at the presence of Hg 2+ , accompanied by the fluorescence color becomes from colorless to bright yellow. It displayed favorable properties like low detection limit (73 nM), extensive pH detection range (5–10) and excellent anti-interference ability. The binding pattern of CS-NA-ITC to Hg 2+ was verified by Job's plot, XPS analysis and FT-IR test. In addition, CS-NA-ITC was utilized to recognition of Hg 2+ in actual water and soil samples and seafood products. Furthermore, the CS-NA-ITC hydrogel could be employed as an efficient Hg 2+ adsorbent with good reusability, which adsorption ability was enhanced compared to chitosan hydrogel.