title: Layer-by-layer assembly of bi-protein/layered double hydroxide ultrathin film and its electrocatalytic behavior for catechol.
abstract: This paper reports the fabrication of a bi-protein/layered double hydroxide (LDH) ultrathin film in which hemoglobin (HB) and horseradish peroxidase (HRP) molecules were assembled alternately with LDH nanosheets via the layer-by-layer (LBL) deposition technique, and its electrocatalytic performances for oxidation of catechol were demonstrated. The results of XRD indicate that the HB-HRP/LDH ultrathin film possesses a long range stacking order in the normal direction of the substrate, with the two proteins accommodated in the LDH gallery respectively as monolayer arrangement. SEM images show that the film surface exhibits a continuous and uniform morphology, and AFM reveals the Root-Mean-Square (RMS) roughness of ∼10.2 nm for the film. A stable direct electrochemical redox behavior of the proteins was successfully obtained for the HB-HRP/LDH film modified electrode. In addition, it exhibits remarkable electrocatalytic activity towards oxidation of catechol, based on the synergistic effect of the two proteins. The catechol biosensor in this work displays a wide linear response range (6-170 μM, r=0.999), low detection limit (5 μM), high sensitivity and good reproducibility.
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
authors.forename: Xianggui
authors.initials: X
authors.lastname: Kong
authors.forename: Xiuying
authors.initials: X
authors.lastname: Rao
authors.forename: Jingbin
authors.initials: J
authors.lastname: Han
authors.forename: Min
authors.initials: M
authors.lastname: Wei
authors.forename: Xue
authors.initials: X
authors.lastname: Duan
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002384:Catalysis; D002396:Catechols / Q000032:analysis* / Q000737:chemistry*; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006454:Hemoglobins / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry*; D006878:Hydroxides / Q000737:chemistry; D008567:Membranes, Artificial; D008839:Microelectrodes; D011485:Protein Binding
chemical_list: D002396:Catechols; D006454:Hemoglobins; D006878:Hydroxides; D008567:Membranes, Artificial; D006735:Horseradish Peroxidase; C034221:catechol