Nitrogen-doped fluorescent active fullerenes as a fluorescent probe for the detection of Hg2+ ions in aqueous solutions

Abstract

Nitrogen-doped fluorescent active fullerenes were designed as fluorescent probe for detecting mercury (II) ions in an aqueous solution. The prepared material was characterized by HR-TEM, FTIR, XPS and XRD analysis. The material was highly crystalline and contained fullerenes encapsulated in between sheets of carbon material, as confirmed by XRD and HR-TEM analysis. The FT-IR spectrum of the prepared material confirmed the successful incorporation of nitrogen in the fullerene structure. The optical property of the prepared sample was analyzed by UV–Visible spectroscopy, and its quenching phenomenon was observed by fluorescence spectroscopy. The fluorescence study shows a good quenching response of mercury (II) ions in comparison to all other tested ions such as Na+, K+, Mg2+, Al3+, Ca2+, Pb2+, Ba2+, Cd2+, Fe3+, Fe2+, Cu2+, Co3+ and Zn2+. A limit of detection (LOD) of 3.5 ppm was attained for Hg2+ ions in a concentration range of 0–25 ppm. These results displayed that nitrogen-rich fullerenes can be used to build a fluorescent probe to remove and detect Hg2+ ions using this unique precursor combined with a nitrogen-rich organic molecule followed by its thermal annealing.