Functional Nanocomposites And General Type Direct Electrochemistry Of Various Redox Proteins

In this study,functional nanocomposites?methoxyl amination polyethylene glycol?mPEG?,functionalization of multi-walled carbon nanotubes?fMWCNTs?,ionic liquid?IL??and the universal direct electrochemistry of a variety of REDOX proteins?biological macromolecule glucose oxidase?GluOx?,catalase?CAT?,superoxide dismutase?SOD?and small molecule biological myoglobin?Myo?,hemoglobin?Hb??were analyzed and realized,respectively.The direct electrochemistry study of REDOX proteins can not only study the performance of the REDOX between protein and electrode,but also study the biomolecular interface effects,interactions,pharmacology etc.These studies also play a certain reference and guidance significance for the construction of new sensors and the research of general purpose direct electrochemistry of REDOX proteins.The amino group in demethoxy-polyethylene glycol,the carboxyl group in multi-walled carbon nanotubes and the ionic liquid may have a better synergistic effect,so as to more effectively regulate the hydrophobicity,stability,conductivity and biocompatibility of functional composite polymer films.The functionalized nanocomposite films were characterized by cyclic voltammetry?CV?,electrochemical impedance spectroscopy?EIS?,ultraviolet-visible spectrophotometer?UV-Vis?,transmission electron microscopy?TEM?and fluorescence spectroscopy.In 50 mM,pH 7.0 phosphate buffer solution,the formal potential and heterogeneous electron transfer constant?ks?of glucose oxidase,catalase,superoxide dismutase,myoglobin and hemoglobin on the composite functional polymer modified glassy carbon were-0.27 V and 6.5 s^-1,-0.13 V and 3.18 s^-1,-0.14 V and 2.17 s^-1,-0.39 V and 3.37 s^-1,-0.38 V and 8.79 s^-1,and they had was a good pair of quasi-reversible REDOX peaks,respectively;And they are in the surface of glassy carbon electrode electrochemical active substance concentration ? 6.23×10-10 mol·cm^-2,1.63×109 mol·cm^-2,4.5×109 mol·cm^-2,5.6×109 mol·cm^-2 and 2.9×109 mol·cm 2,respectively.On the basis of this paper,the optimum pH of the fully modified electrode of glucose oxidase is 7.0 in the phosphate buffer solution of 50 mM.The modified electrode could recognize and detect glucose linearly in the range of 20 to 950 ?M with a detection limit of 0.2 ?M,a novel sensor for glucose detection has been successfully constructed.The michaelis-menten constant?Kmapp?of NF/GluOx/IL/mPEG-fMWCNTs/GCE was 143 ?M.The anti-interference ability and stability,the real samples were determined of the NF/GluOx/IL/mPEG-fMWCNTs modified electrode was studied.The IL/mPEG-fMWCNTs functional polymer could preserve the conformational structure and catalytic activity of GluOx and lead to high sensitivity,stability,and selectivity of the biosensors for glucose recognition and detection.