Electrochemical behaviour of Sudan I at Fe3O4 nanoparticles modified glassy carbon electrode and its determination in food samples

In this work, a simple and sensitive electrochemical method was developed to determine Sudan I based on magnetic Fe3O4 nanoparticles modified glassy carbon electrode using cyclic voltammetry and differential pulse voltammetry. The sensor exhibited an obviously electrocatalytic activity towards the oxidation of Sudan I, which can be confirmed by the increased oxidation peak current and the decreased oxidation peak potential when compared with the bare GCE. The determination conditions, such as pH, modifier amount, accumulation time and accumulation potential, were optimised. And some kinetic parameters were calculated. Under the optimum experimental conditions, the oxidation current of Sudan I was proportional to its concentration from 0.01 to 1 μM and 1 to 20 μM. The detection limit was estimated to be 0.001 μM (S/N = 3). The developed method was successfully applied to determine Sudan I content in food samples with satisfactory results.