Fe3O4@MXene/rGO/PANI Composite: A Novel Sensing Material for the Electrochemical Detection of Orange II and Rhodamine B Food Dyes

Abstract The sensitive and selective monitoring of food dyes is essential due to their potential carcinogenic effects on human as well as on living organisms. Herein, Fe3O4@MXene/rGO/PANI nanocomposite was prepared and successfully applied as a recognition layer for the sensitive and fast analysis of Orange II (OR II) and Rhodamine B (RB) via DPV. The prepared nanocomposites were described by XRD, SEM and FTIR analysis. The XRD results verified the crystalline nature of the composite. Successful fabrication of electrode surface was confirmed from CV, EIS and CC. Due to the outstanding electrochemical characteristics, high surface area, and good electrocatalytic activity of Fe3O4@MXene/rGO/PANI, the peak currents of dyes on modified GC electrode are considerably higher than among all studied electrodes. The detection conditions such as supporting electrolyte, amount of modifier, pH of the medium, accumulation potential and time were studied and optimized. Under optimized conditions, the designed sensor exhibited two linear ranges from 0.005–0.1 and 0.1–1 µM with detection limits of 0.56 nM and 0.42 nM for OR II and RB, which was attributed to the high surface area, strong accumulation ability and multiple active sites of Fe3O4@MXene/rGO/PANI. Futhermore, the stability of the designed sensor was analyzed for the detection of OR II and RB. The practical applicability of this sensor was also scrutinized for the analysis of OR II and RB in real samples and suitable results were obtained. Hence, this simple and effective methodology for detection of dyes has good potential for monitoring of environmental pollutants.