纳米二氧化钛对尿素酶活性的增强效应  

Enhancement of urease activity by TiO_2 nanoparticles

作　　者：司士辉[1] 李赛[1] 杨政鹏[1] 谢亚林[1] 

机构地区：[1]中南大学化学化工学院,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2007年第4期692-695,共4页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(20475065)

摘　　要：分别用粒径为5 nm,25 nm和2.4μm的TiO2吸附尿素酶。在35℃,pH为7的条件下采用电位法测定吸附在TiO2上的尿素酶的活性变化。基于纳米TiO2膜的pH响应,制备尿素酶/纳米TiO2复合膜电极。研究结果表明：纳米TiO2对尿素酶的活性有明显的增强效应,其游离酶及TiO2（粒径分别为5 nm,25 nm和2.4μm）固载酶的米氏常数分别为0.45,0.22,0.28和0.31 mol/L。该复合电极对尿素的检测范围为8.5×10^-5-0.15 mol/L,相关系数为0.993 73,检出限为5×10^-6 mol/L,其使用寿命在35 d后仍能维持38%。The urease was adsorbed on TiO2 with different particle sizes（5 nm, 25 nm, 2.4 μm）. Under conditions of 35 ℃ and pH=7, the activity of urease absorbed on TiO2 particles was measured by potentiometry. Based on the pH response of nano-TiO2 film, a urease/nano-TiO2 complex films electrode was developed. The results show that the activity of urease can be enhanced by being adsorbed on nanostructure materials, and the Michaelis-Menton constant of free and urease adsorbed on different particles sizes of TiO2 （5 nm, 25 nm, 2.4 μm） are 0.45, 0.22, 0.28 and 0.31 mol/L, respectively. The complex films electrode is sensitive to urea in the linear range 8.5× 10^-5-0.15 mol/L, the correlation coefficient and the detection limit are 0.993 73 and 6×10^-5 mol/L, respectively. The lifetime of the urease/nano-TiO2 complex films electrode can remain 38% after 35 d.

关 键 词：纳米TIO2 酶吸附 尿素酶 复合电极 

分 类 号：O614.411[理学—无机化学]