Naphthalimide-functionalized Fe3O4@SiO2 core/shell nanoparticles for selective and sensitive adsorption and detection of Hg2+

A novel 1,8-naphthalimide-functionalized Fe 3 O 4 @SiO 2 core/shell magnetic fluorescent nanoparticles ( MFNPs ) for simultaneous detection and adsorption of Hg 2+ was designed and synthesized. A series of adsorption studies were carried out with various Hg 2+ concentrations, temperature, time and pH. The maximum adsorption capacity is higher than 30   mg/g over a broad temperature (0   °C, 25   °C, and 50   °C) and pH (4–10). The results showed that MFNPs possesses an excellent reusability and the high adsorption specificity toward Hg 2+ . The detection limit for Hg 2+ is 3.4   nM. In addition, owing to the aggregation of MFNPs occurring in the Hg 2+ aqueous solution, the adsorbent was separated easily by the settlement or the external magnetic field, which facilitated the removal of Hg 2+ .