一种新的纳米金半网状膜的酶生物电化学传感器

以纳米金为载体, 己二硫醇(HDT)为交联剂, 构建了一种半网状酶标纳米金, 有效地增大了酶的固定量. 以此半网状酶标纳米金修饰电极构建敏感界面, 用于计时电流法检测H2O2, 并与无交联剂酶标纳米金构建的传感器进行比较. 结果表明, 半网状酶标纳米金构建的界面稳定性好, 电流响应灵敏度高, 能对低浓度H2O2进行准确检测, 检出限达0.08 μmol/L. 分别用UV-Vis光谱和透射电镜对半网状酶标纳米金进行了表征. 同时用电化学阻抗、石英晶体微天平及循环伏安法对此半网状修饰膜构建的界面进行了研究.     

Effects of growing conditions on the electric and magnetic properties of strained La2/3Sr1/3MnO3 thin films

We investigate the growing condition dependences of magnetic and electric properties of the La_2/3Sr_1/3MnO₃ thin films grown on SrTiO₃（001） substrates.With reducing the film thickness and growth pressure,the Curie temperature（T_c）drops off,and the magnetism and metallicity are suppressed.At an appropriate deposition temperature,we can obtain the best texture and remarkably enhance the magnetic and electrical properties.However,the resistivity of film cannot be modulated by changing the dc current and green light intensity.This result may be induced by the coherent strains in the epitaxially grown film due to its lattice mismatching that of the SrTiO₃ substrate.Furthermore,we show that the relations between the magnetism and the resistivity for the typical films with different thickness values.For the 13.4-nm-thick film,the R-T curve presents two transition behaviors:insulator-to-metal and metal-to-insulator in the cooling process:the former corresponds to magnetic transition,and the later correlates with thermal excitation conduction.