Fluorophore-modified Fe3O4-magnetic-nanoparticles for determination of heavy metal ions in water

A prototype of fluorescence sensor, based on 1,4-dihydroxyanthraquinone (1,4-DHAQ) derivative and 9-fluorenylmethyl chloroformate (Fmoc-Cl) co-modified Fe3O4 magnetic nanoparticals (MNPs) (denoted as 1,4-DHAQ/Fmoc-Cl co-modified Fe3O4 MNPs), has been achieved via solvothermal synthesis of amine-functionalized Fe3O4 MNPs and subsequent surface co-modification of 1,4-DHAQ derivative and Fmoc-Cl onto the Fe3O4 MNPs. The 1,4-DHAQ/Fmoc-Cl co-modified Fe3O4 MNPs can be used for not only simple rapid qualitative detection of Cu2+, Cd2+, Zn2+ and Hg2+ in aqueous solution, but also quantitative analysis of the above four heavy metal ions with lower detection limits of 8 × 10−9, 1.5 × 10−8, 10−8 and 10−8 M, respectively. This is the first prototype of fluorescence sensor that has potentials in the detection of Cu2+, Cd2+, Zn2+ and Hg2+ in aqueous solutions and even in drinking water. The sensor designing idea might be extended to other multifunctional chemosensors.