Mesoporous MgO nanosheets: 1,6-hexanediamin-assisted synthesis and their applications on electrochemical detection of toxic metal ions

•The mesoporous MgO nanosheets were successfully synthesized.•The product was used to construct an electrochemical sensor on GCE.•The electrode was applied to determine Hg(II), Cu(II), Pb(II) and Cd(II).•The sensor exhibits high sensitivity and selectivity.

The mesoporous MgO nanosheets with uniformly distributed mesoporosity and high specific surface area of 102.8 m2/g were simply synthesized on a large scale by calcination of hexagonal Mg(OH)2 nanosheet precursor, which was prepared using 1,6-hexanediamin-assisted solution approach. The as-prepared mesoporous MgO nanosheets were used to construct a cheap, easy and environmentally-friendly electrochemical sensor on glassy carbon electrode for the simultaneous and selective electrochemical determination of four toxic metal ions of Hg(II), Cu(II), Pb(II) and Cd(II) in an aqueous solution, which exhibits high sensitivity and selectivity. The DPV responses of the sensor toward separate measurements of Hg(II), Cu(II), Pb(II) and Cd(II) at different concentrations show the linear detection range was 0.005–1.71, 0.01–2.13, 0.01–2 and 0.01–0.21 μM. The simultaneous and selective determination of these species in the quaternary mixtures presents the linear responses in the range of 0.005–1.71, 0.01–1.92, 0.01–1.76 and 0.01–0.2 μM. The favorable performance makes this sensor extremely attractive for onsite environmental monitoring of heavy metal ions.