Fe3O4/CoFe nanoparticles decorated 3D hierarchical nitrogen-doped carbon nanosheets for synchronous measurement of sunset yellow and tartrazine

Electrocatalyst with high accumulation capacity and efficient electrocatalysis are crucial for constructing electrochemical sensors. In this study, 3D hierarchical nitrogen-doped carbon nanosheets decorated by Fe 3 O 4 /CoFe nanoparticles (Fe 3 O 4 /CoFe@N-CSs) were successfully prepared. The morphology, composition, microstructure, and property were investigated by SEM, HRTEM, XRD, XPS, and cyclic voltammetry. The synthesized Fe 3 O 4 /CoFe@N-CSs were assembled by two-dimensional (2D) nanosheets to form flower-like layered structure. It displayed a large amount of pore space for promoting the accumulation of targets and brilliant electrocatalysis towards the electrochemical oxidation of sunset yellow (SY) and tartrazine (TTZ). Using Fe 3 O 4 /CoFe@N-CSs to modify screen-printed electrode (SPE), a disposable electrochemical sensor (Fe 3 O 4 /CoFe@N-CSs/SPE) was constructed for the analysis of SY and TTZ. It showed the detection range of 0.008–5.0 μM and 0.02–10.0 μM with the detection limit of 2.0 nM and 4.0 nM, respectively. The practical applicability of the sensor in real drink samples provided satisfactory data. The results indicated that Fe 3 O 4 /CoFe@N-CSs was a promising nanomaterial, contributing great potential for individual and synchronous measurement of trace amounts of SY and TTZ in food samples.