An efficient electrochemical sensor based on three-dimensionally interconnected mesoporous graphene framework for simultaneous determination of Cd(II) and Pb(II)

Recently, ordered mesoporous carbon has displayed attractive performance in electrochemical catalysis and sensing, benefiting from its rich and tunable pore texture. In this work, a novel electrochemical sensor based on a three-dimensionally interconnected mesoporous graphene framework (MGF) was developed for simultaneous determination of Cd(II) and Pb(II) in aqueous solution. Attributable to the abundant three-dimensional mesopores and good electrical conductivity of MGF, as well as the synergistic effect of Nafion and in-situ plated bismuth films, a highly sensitive determination of mixed metals at a Bi/MGF-Nafion/GCE is achieved. The proposed sensor exhibits wide linear responses for Cd(II) and Pb(II), ranging from 2–70   μg   L −1 and 0.5–110   μg   L −1 , respectively. The detection limits are about 0.5 and 0.1   μg   L −1 for Cd(II) and Pb(II), respectively, which are about 6 and 100 times lower than the drinking water standards set by the World Health Organization (WHO). Moreover, Bi/MGF-Nafion/GCE has been applied for the detection of mixed metals in real water samples. The satisfying recoveries (87.5-109.2%) and relative standard deviations (RSD, 3.7-8.6%) make the proposed electrode a promising candidate for rapid and on-site monitoring of environmental metallic pollutants.