Direct electrochemistry and electrocatalytic characteristic of heme proteins immobilized in a new sol-gel polymer film.
Heme proteins were immobilized on glass carbon electrodes by poly (N-isopropylac-yamide-co-3-methacryloxy-propyl-trimethoxysilane) (PNM) and exhibited a pair of well-defined, quasi-reversible cyclic voltammetric peaks at about -0.35 V versus a saturated calomel electrode in pH 7.0 buffer solution, corresponding to hemeFe(III)+e-->hemeFe(II). Some electrochemical parameters were calculated by performing nonlinear regression analysis of square wave voltammetry (SWV) experimental data. The formal potential was linearly dependent on pH, indicating the electron transfer of Fe(III)/Fe(II) redox couple accompanied by the transfer of proton. Ultraviolet visible and Fourier transform infrared spectra suggested that the conformation of proteins in the PNM films retained the essential feature of its native secondary structure. Atomic force microscopy images demonstrated the existence of interaction between heme proteins and PNM. N,N-dimethylformamide (DMF) played an important role in immobilizing proteins and enhancing electron transfer between proteins and electrodes. Electrochemical catalytic reductions of hydrogen peroxide and trichloroacetic acid by proteins entrapped in PNM film were also discussed, showing the potential applicability of the film modified electrodes as a biosensor.
Sun
Yi-Xin
YX
Ministry-of-Education, Key Laboratory for the Synthesis and Application of Organic Functional Molecules, and College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, PR China.
Wang
Sheng-Fu
SF
D000818:Animals; D002374:Catalase / Q000737:chemistry / Q000378:metabolism; D002384:Catalysis; D002417:Cattle; D004126:Dimethylformamide; D017097:Electric Impedance; D004563:Electrochemistry; D004566:Electrodes; D006420:Hemeproteins / Q000737:chemistry* / Q000378:metabolism; D006454:Hemoglobins / Q000737:chemistry / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008027:Light; D018625:Microscopy, Atomic Force; D009211:Myoglobin / Q000737:chemistry / Q000378:metabolism; D044367:Phase Transition; D011108:Polymers / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013057:Spectrum Analysis; D014466:Ultraviolet Rays
D006420:Hemeproteins; D006454:Hemoglobins; D009211:Myoglobin; D011108:Polymers; D012821:Silanes; C526658:poly(N-isopropylac-yamide-co-3-methacryloxy-propyl-trimethoxysilane); D004126:Dimethylformamide; D006861:Hydrogen Peroxide; D002374:Catalase