Simultaneous electrocatalytic determination of lead and cadmium ions employing a poly(methylene blue)/graphene modified glassy carbon electrode

Abstract

Employing a poly(methylene blue)/graphene modified glassy carbon electrode (PMB/Gr/GCE) electrode, a sensitive and convenient method for the simultaneous determination of lead and cadmium ions (Pb2+ and Cd2+) was developed by cyclic voltammetry. The electrochemical behavior of these two species at the PMB/Gr/GCE was investigated by cyclic voltammetry. Experimental results showed that the oxidation peak currents corresponding to the two species were significantly increased at the modified electrode and this was further used to determine them. Under optimized analytical conditions, the oxidation peak currents corresponding to both species showed linear dependence on their concentration in the range from 4.00 × 10−8 to 1.60 × 10−5 mol L−1. The detection limits for Pb2+ and Cd2+ were 1.00 × 10−8 mol L−1 and 1.20 × 10−8 mol L−1, respectively. The developed method showed several advantages over reported voltammetric methods, such as high sensitivity, wide linear range, low detection limits and good recoveries. The applicability of the developed method has been demonstrated utilizing real sea shrimp and river water samples.