中文摘要：

将辣根过氧化物酶（HRP）固定到凹凸棒石粘土（Attapulgite,简称凹土）表面,制得HRP-凹土纳米复合物（HRP-Attapulgite）,并采用电化学阻抗、紫外光谱和红外光谱技术表征了HRP固定化过程.HRP-Attapulgite电化学性质测试表明,凹土能促进HRP的直接电子转移,其循环伏安曲线有一对良好的氧化还原峰,峰电位分别为Epc=-370 mV,Epa=-300 mV,式量电位E0′=-335 mV.凹土表面HRP的H2O2响应电流与浓度（0.3-75μmol·L-1）呈线性关系.该电极可用于巨噬细胞中微量H2O2的测定.

英文摘要：

The nanostructured attapulgite clay was employed as a support matrix for immobilizing horseradish peroxidase（HRP）.FTIR and electrochemical methods demonstrated that HRP had been effectively assembled on attapulgite surface with the formation of HRP-Attapulgite nanocomposites.The HRP-Attapulgite hybrid was deposited on the glassy carbon（GC） electrode forming the HRP-Attapulgite/GC electrode.Cyclic voltammetric results showed a pair of well-defined redox peaks,which were ascribed to direct electron transfer（DET） of HRP,with the formal potential E0′=-335 mV（vs.SCE） in the phosphate buffer solution（PBS,pH 7.0）.The dependence of E0′on solution pH indicated that DET reaction of HRP was coupled with proton transfer.The developed electrode revealed a good electrocatalytical activity toward the reduction of H2O2.The electrocatalyic current was linear to the concentration of H2O2 in the concentration range of 0.3 to 75 μmol·L-1with high sensitivity（（53 ± 2） μA·（mmol·L-1）-1·cm-2）and low detection limit（（0.10 ± 0.05） μmol·L-1）.Moreover,the HRP-Attapulgite/GC electrode was used to detect the level cellular H2O2 released from the Macrophages cells（RAW 264.7）.Therefore,an electrochemical approach for detection of cellular H2O2 based on HRP-Attapulgite hybrid was developed.This study has not only established a novel approach to detect cellular H2O2,but also provided a general route for fabricating attapulgite-based biosensing platform via assembling enzymes/proteins on attapulgite surface,expanded the scope of attapulgite applications to the field of bioelectroanalytical chemistry and cellular biology.