title: Direct electrochemistry and electrocatalysis based on film of horseradish peroxidase intercalated into layered titanate nano-sheets.
abstract: Intercalation of horseradish peroxidase (HRP) into layered titanate by assembling it with titanate nano-sheets (TNS) was firstly used for fabrication of enzyme electrode (HRP-TNS electrode). XRD result revealed that HRP-TNS film featured layered structure with HRP monolayer intercalated between the titanate layers. UV-vis spectra result indicated the intercalated HRP in TNS film well retained its native structure. The HRP-TNS film was uniform with porous structures which were confirmed by SEM. The immobilized HRP in the TNS film exhibited fast direct electron transfer and showed a good electrocatalytic performance to H2O2 with high sensitivity, wide linear range and low detection. The excellent electrochemical performance of the HRP-TNS electrode was attributed to biocompatibility of the titanate sheets, porous architectures of the HRP-TNS film which retained activity of HRP to large extent, avoided aggregation of HRP, provided better mass transport and allowed more HRP loading per unit area. Thus, the simple method described here provides a novel and effective platform for immobilization of enzyme in realizing direct electrochemistry and has a promising application in fabrication of the third-generation electrochemical biosensors.
authors.affiliation: Department of Chemistry, Key Lab of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 100084, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Xianbo
authors.initials: X
authors.lastname: Lu
authors.forename: Jinghong
authors.initials: J
authors.lastname: Li
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002384:Catalysis; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006735:Horseradish Peroxidase / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014025:Titanium / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D004800:Enzymes, Immobilized; C009495:titanium dioxide; D006861:Hydrogen Peroxide; D014025:Titanium; D006735:Horseradish Peroxidase