Cyclic Voltammetric Determination of H2O2 with Poly-L-Lysine/Multi-wall Carbon Nanotubes Modified Glassy Carbon Electrode

Multi-wall nano-carbon tubes(MWCNT′s) was dispersed in DMF and dropped on the surface of glassy carbon electrode (GCE), which was polymerised electrochemically in 0.01 mol·L-1 L-lysine solution of pH 6.7 at the potential range of 1.0-2.5 V (vs.Ag/AgCl) to prepare poly-L-lysine/MWCNT′s modified electrode (abbr. as PLL/MWCNT′s/GCE). The electrochemical property of the modified electrode was studied by cyclic voltammetry. It was found that the modified electrode exhibited excellent electrocatalytic responses towards the reduction of H2O2. Based on this finding, a selective method for determination of H2O2 by cyclic voltammetry was proposed. Linear relationship between values of peak current and concentration of H2O2 was obtained in the range of 4.3×10-4-1.3×10-2mol·L-1, with detection limit of 1.5×10-4mol·L-1. Test for recovery was made by standard addition method, and values of recovery found were in the range of 92.4%-105%.