Ultrasensitive electrochemical determination of tyrosine based on the α-Fe2O3@Co3O4-NRGO modified electrode

An electromical sensor based on α-Fe 2 O 3 @Co 3 O 4 -NRGO composited glass carbon electrode (GCE) was constructed and used for ultrasensitive tyrosine detection. A series of characterization techniques including scanning electron microscopy, X-ray diffraction and electrochemical impedance spectroscopy technique and cyclic voltammetry were employed to investigate the modified electrode. Compared with the bare GCE, the α-Fe 2 O 3 @Co 3 O 4 -NRGO/GCE exhibited a strong current response to tyrosine because of the synergistic effect of ternary composite. Under optimized conditions, the peak currents that responded to tyrosine concentration had a linear relationship from the scope of 0.01 to 10 µM (R 2  = 0.9977) by second derivative linear sweep voltammetry (SDLSV) and 8 nM (S/N = 3) is the detection limit. The sensor showed higher sensitivity, better repeatability, reproducibility and greater sensing stability related advantages over those in previous tyrosine detections. Furthermore, the sensor was successfully applied to trace tyrosine determination in practical samples such as milk and serum.