Rapid Detection of Nitrofuran and Its Metabolites by Using Carboxylic Multi-walled Carbon Nanotubes Modified Glassy Carbon Electrode

An electrochemical method using carboxylic multi-walled carbon nanotubes (MWCNTs-COOH) modified glassy carbon electrode (GCE) was described for detecting nitrofurazone (NF) and semicarbazide (SEM) residual. The chemical structure and morphological features of carboxylic multi-walled carbon nanotubes were determined by FTIR spectroscopy and scanning electron microscope. The electrochemical behavior of NF and SEM on MWCNTs-COOH/GCE was also investigated by cyclic voltammetry (CV). And the effect of the buffer pH and scan rate was optimized. Under the optimized experimental conditions, the linear relationship between the peak current and the concentration of NF and SEM was determined using the amperometry (AMP). The linear relationship of NF was Ip(μA) =-21.050-0.095c(μmol L-1), r = 0.999, with a detection limit of 2.24×10-7 mol L-1 (S/N=3). The linear relationship of SEM was Ip(μA) =-0.269+0.0599c(mol L-1), r=0.998, with a detection limit of 1.88×10-7 mol L-1 (S/N=3). Finally, the modified electrode was successfully applied in the real sample and the average recoveries for NF and SEM were 91.1~94.0% and 92.9~98.0%, respectively.