title: Single-crystal CeO2 nanocubes used for the direct electron transfer and electrocatalysis of horseradish peroxidase.
abstract: 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.
authors.affiliation: College of Chemistry and Chemical Engineering, Graduate University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Xiao
authors.forename: Qingfen
authors.initials: Q
authors.lastname: Luan
authors.forename: Xin
authors.initials: X
authors.lastname: Yao
authors.forename: Kebin
authors.initials: K
authors.lastname: Zhou
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002384:Catalysis; D002563:Cerium / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004579:Electron Transport; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006735:Horseradish Peroxidase / Q000032:analysis* / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D002563:Cerium; C030583:ceric oxide; D006735:Horseradish Peroxidase