Simultaneously determination of trace Cd2+ and Pb2+ based on L-cysteine/graphene modified glassy carbon electrode

In this paper, L-cysteine/graphene-CS/GCE (L-cys/GR-CS/GCE) was prepared successfully, and its electrochemical properties were characterized by cyclic voltammetry (CV) and electrochemical AC impedance. Moreover, the electrochemical behaviors of Cd2+ and Pb2+ on the proposed electrode were studied by differential pulse anodic stripping voltammetry (DPASV). Experimental parameters, such as the deposition potential and time, the pH value of buffer solution, were optimized. Under the optimized conditions, the linear equations of the DPASV response current with Cd2+ and Pb2+ concentration were I (mu A) = 0.745 C (mu g/L) + 4.539 (R = 0.9986), I (mu A) = 0.437 C (mu g/L) + 2.842 (R = 0.9983), respectively, and the detection limit was 0.45 and 0.12 mu g/L, respectively. Finally, L-cys/GR-CS/GCE was used to detect Cd2+ and Pb2+ in practical samples, and the results were compared with ICP-AES. This idea and method will provide a new approach for food security evaluation. (C) 2015 Elsevier Ltd. All rights reserved.