Simultaneous detection and removal of metal ions based on a chemosensor composed of a rhodamine derivative and cyclodextrin-modified magnetic nanoparticles

A variety of chemosensors have been reported for detection of metal ions. However, the metal ions could not be separated and removed at the same time for the goal of water purification. This paper presents to detect and remove metal ions from aqueous solution simultaneously by a fluorescence chemosensor and functional magnetic nanoparticles. A novel probe adamantyl (AD)–maleic anhydride (MAH)–rhodamine B (RhB) was designed and synthesized from RhB, ethylene diamine, MAH, and AD. AD–MAH–RhB showed high selectivity and sensitivity to metal ions in aqueous solution. The sensing mechanism was explored by FTIR and mass spectra. The results suggested that AD–MAH–RhB could conjugate with metal ions and form the binding complexes with various stoichiometries of probe and metal ions. Moreover, β-cyclodextrin-modified magnetic nanoparticles (CD-MNP) were fabricated and used as host materials to form inclusion complex of CD-MNP and AD–MAH–RhB-metal ions. Then, the metal ions could be removed by an outer magnet, which were confirmed by fluorescent spectrum. The probe and CD-MNP had the great potential application for sewage treatment.