聚L-赖氨酸-多壁碳纳米管修饰玻碳电极循环伏安法测定过氧化氢
Cyclic Voltammetric Determination of H2O2 with Poly-L-Lysine/Multi-wall Carbon Nanotubes Modified Glassy Carbon Electrode
-
摘要: 将多壁碳纳米管分散在N,N-二甲基甲酰胺中并滴涂在玻碳电极(GCE)表面,然后将该电极置于pH 6.7的0.01 mol·L-1 L-赖氨酸溶液中,于电位1.0~2.5 V范围内进行电聚合,制备了聚L-赖氨酸-多壁碳纳米管修饰电极(PLL/MWCNT′s/GCE)。采用循环伏安法对修饰电极的电化学性能进行了表征。研究发现,在pH 7.0的磷酸盐缓冲溶液中,该修饰电极对过氧化氢具有明显的电催化还原作用,据此提出了用循环伏安法测定过氧化氢的含量。过氧化氢的还原峰电流与其浓度在4.3×10-4~1.3×10-2mol·L-1之间呈线性关系,检出限(3S/N)为1.5×10-4mol·L-1。采用标准加入法进行回收试验,方法的回收率在92.4%~105%之间。Abstract: 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%.
下载: