Electrochemical Immunosensor for Melamine Determination Based on Graphene-Chitosan Composite Film Modified Electrode

An electrochemical immunosensor for the determination of melamine based on graphene-chitosan modified electrode was constructed.Indirect competitive electrochemical immunoassay was performed to determine melamine in aqueous solutions.Cyclic voltammetry(CV) and differential pulse voltammetry(DPV) were carried out to monitor the fabrication steps of immunoreaction system in solutions containing K3Fe(CN)6 as redox probe.The immunosensor demonstrated excellent melamine detection features with a broad linear range of 5 to 1500 ng/mL and a detection limit of 0.2 ng/mL.A good recovery of melamine in the range of 104%–106.2% was obtained in spiked milk samples.