Xiao Xiaoling, Luan Qingfen, Yao Xin, Zhou Kebin
College of Chemistry and Chemical Engineering, Graduate University of Chinese Academy of Sciences, Beijing 100049, China.
Biosens Bioelectron. 2009 Apr 15;24(8):2447-51. doi: 10.1016/j.bios.2008.12.020. Epub 2008 Dec 25.
A new horseradish peroxidase (HRP) third-generation electrochemical biosensor based on ceria nanocubes (CeO(2)-NCs) and chitosan (Chit) was developed. The single-crystalline, uniform and size-controlled CeO(2)-NCs have been synthesized by hydrothermal method. HRP was immobilized in CeO(2)-NCs and Chit film on the glass carbon electrode (HRP/CeO(2)/Chit/GCE). Compared with HRP-chitosan modified electrode (HRP/Chit/GCE), HRP/CeO(2)/Chit/GCE exhibited a pair of more obvious redox peaks at -0.348 V (versus Ag/AgCl). Experimental results indicate CeO(2)-NCs greatly promoted the electron transfer between HRP and GCE. The immobilized HRP exhibited direct electrochemical behavior toward the reduction of hydrogen peroxide (H(2)O(2)). The resulting biosensor showed a linear range of 1-150 microM and a detection limit of 0.26 microM estimated at a signal-to-noise ratio of 3. Stability and reproducibility of the biosensor were also studied. The biological activity of HRP immobilizing in the composite film was characterized by UV-vis and FTIR spectra.
基于二氧化铈纳米立方体（CeO₂-NCs）和壳聚糖（Chit）开发了一种新型辣根过氧化物酶（HRP）第三代电化学生物传感器。通过水热法合成了单晶、均匀且尺寸可控的CeO₂-NCs。HRP固定在玻璃碳电极上的CeO₂-NCs和Chit膜中（HRP/CeO₂/Chit/GCE）。与HRP-壳聚糖修饰电极（HRP/Chit/GCE）相比，HRP/CeO₂/Chit/GCE在-0.348 V（相对于Ag/AgCl）处表现出一对更明显的氧化还原峰。实验结果表明CeO₂-NCs极大地促进了HRP与GCE之间的电子转移。固定化的HRP对过氧化氢（H₂O₂）的还原表现出直接电化学行为。所得生物传感器的线性范围为1-150 μM，在信噪比为3时估计检测限为0.26 μM。还研究了生物传感器的稳定性和重现性。通过紫外可见光谱和傅里叶变换红外光谱对固定在复合膜中的HRP的生物活性进行了表征。
