A simple and sensitive method for the determination of 4-n-octylphenol based on multi-walled carbon nanotubes...

A simple and sensitive electroanalytical method was presented for the determination of 4-n-octylphenol (OP) based on multi-walled carbon nanotubes (MWCNTs) modified glassy carbon electrode (GCE). OP was directly oxidized on the MWCNTs/GCE, and the electrochemical oxidation mechanism was demonstrated by a one-electron and one-proton process in the reaction. The oxidation peak current of OP was significantly enhanced by the use of MWCNTs/GCE compared with those of bare glassy carbon electrode, suggesting that the modified electrode can remarkably improve the performance for OP determination. Factors influencing the detection processes were optimized. Under these optimal conditions, a linear relationship between concentration of OP and current response was obtained in the range of 5 x 10(-8) to 1 x 10(-5) mol/L with a detection limit of 1.5 x 10(-8) mol/L and correlation coefficient 0.9986. The modified electrode showed good selectivity, sensitivity, reproducibility and high stability.