An electrochemical investigation of hemoglobin and catalase incorporated in collagen films.
Collagen, an electrochemically inert protein, formed films on pyrolytic graphite (PG) electrodes, which provided a suitable microenvironment for heme proteins to transfer electron directly with the underlying electrodes. Hemoglobin (Hb) and catalase (Cat) incorporated in collagen films exhibited a pair of well-defined and quasi-reversible cyclic voltammetric peaks at around -0.35 V and -0.47 V (vs. SCE) in pH 7.0 buffers, respectively, characteristic of the protein heme Fe(III)/Fe(II) redox couples. UV-vis spectra showed that the heme proteins in collagen films retained their near-native conformations in the medium pH range. The results of scanning electron microscopy (SEM) demonstrated that the interaction between heme proteins and collagen made the morphology of dry protein-collagen films different from the collagen films alone. The electrochemical parameters such as apparent heterogeneous electron transfer rate constant (k(s)) and formal potential (E degrees ') of the films were estimated by using square wave voltammograms (SWV) and nonlinear regression analysis. The heme protein-collagen film electrodes were also used to catalyze the reduction of nitrite, oxygen and hydrogen peroxide, indicating potential applications of the films for the fabrication of a new type of biosensor that does not use mediators.
Li
Min
M
Department of Chemistry, Beijing Normal University, Beijing 100875, China.
He
Pingli
P
Zhang
Yan
Y
Hu
Naifei
N
D000818:Animals; D015374:Biosensing Techniques; D002374:Catalase / Q000737:chemistry*; D002417:Cattle; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003094:Collagen / Q000737:chemistry*; D004566:Electrodes; D004579:Electron Transport; D006108:Graphite / Q000737:chemistry; D006420:Hemeproteins / Q000737:chemistry*; D006454:Hemoglobins / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D013056:Spectrophotometry, Ultraviolet
D020099:Coated Materials, Biocompatible; D006420:Hemeproteins; D006454:Hemoglobins; D006108:Graphite; D003094:Collagen; D002374:Catalase