ABSTRACT
In this study, glucose oxidase and polyphenol oxidase were immobilized in conducting polymer matrices; polypyrrole and poly(N-(4-(3-thienyl methylene)-oxycarbonyl phenyl) maleimide-co-pyrrole) via electrochemical method. Fourier transform infrared and scanning electron microscope were employed to characterize the copolymer of (N-(4-(3-thienyl methylene)-oxycarbonyl phenyl) maleimide) with pyrrole. Kinetic parameters, maximum reaction rate and Michealis-Menten constant, were determined. Effects of temperature and pH were examined for immobilized enzymes. Also, storage and operational stabilities of enzyme electrodes were investigated. Glucose and polyphenol oxidase enzyme electrodes were used for determination of the glucose amount in orange juices and human serum and phenolic amount in red wines, respectively.
Subject(s)
Catechol Oxidase , Enzymes, Immobilized , Glucose Oxidase , Beverages , Blood Glucose/analysis , Catechol Oxidase/metabolism , Citrus sinensis/chemistry , Electrochemistry , Enzyme Stability , Enzymes, Immobilized/metabolism , Glucose/analysis , Glucose Oxidase/metabolism , Humans , Hydrogen-Ion Concentration , Kinetics , Macromolecular Substances/chemical synthesis , Macromolecular Substances/chemistry , Microscopy, Electron, Scanning , Phenols/analysis , Polymers/chemical synthesis , Polymers/chemistry , Pyrroles/chemical synthesis , Pyrroles/chemistry , Spectroscopy, Fourier Transform Infrared , Temperature , Wine/analysisABSTRACT
Immobilization of invertase in conducting copolymer matrices of 3-methylthienyl methacrylate with pyrrole and thiophene was achieved by constant potential electrolysis using sodium dodecyl sulfate (SDS) as the supporting electrolyte. Polythiophene (PTh) was also used in entrapment process for comparison. Kinetic parameters, Michaelis-Menten constant, K(m), and the maximum reaction rate, V(max), were investigated. Operational stability and temperature optimization of the enzyme electrodes were also examined.
Subject(s)
Enzymes, Immobilized/chemistry , Polymethyl Methacrylate/chemistry , Thiophenes/chemistry , beta-Fructofuranosidase/chemistry , Electrochemistry , Enzymes, Immobilized/metabolism , Kinetics , Microscopy, Electron, Scanning , Pyrroles/chemistry , Sodium Dodecyl Sulfate/chemistry , Surface Properties , Temperature , beta-Fructofuranosidase/metabolismABSTRACT
Glucose oxidase (GOD) was immobilized in four different conducting polymer matrices, namely: polypyrrole, (PPy), poly(pyrrole-graft-polytetrahydrofuran), (1) and (3); and poly(pyrrole-graft-polystyrene/polytetrahydrofuran), (2). The kinetic parameters V(max) and K(m), and the optimum temperature were determined for both immobilized and native enzymes. The effect of electrolysis time and several supporting electrolytes, p-toluenesulfonic acid, p-toluene sulfonic acid (PTSA), sodium p-toluene sulfonate, sodium p-toluene sulfonate (NaPTS), and sodium dodecyl sulfate, sodium dodecyl sulfate (SDS), on enzyme immobilization were investigated. The high K(m) value (59.9 mM) of enzyme immobilized in PPy was decreased via immobilization in graft copolymer matrices of pyrrole. V(max), which was 2.25 mM/min for pure PPy, was found as 4.71 mM/min for compound (3).
Subject(s)
Furans/chemistry , Glucose Oxidase/chemistry , Polymers/chemistry , Polystyrenes/chemistry , Pyrroles/chemistry , Electrolysis , Electrolytes , Kinetics , Temperature , Time FactorsABSTRACT
Immobilization of invertase in thiophene-capped poly(methylmethacrylate)/polypyrrole matrices was achieved by constant potential electrolysis using different supporting electrolytes. Optimum reaction conditions such as substrate concentration, temperature, and pH for the enzyme electrodes were determined. The temperature and pH were found to be 60 degrees C and 4.8, respectively. The effect of supporting electrolyte on the enzyme activity revealed that SDS was the best in the immobilization procedure. Michaelis-Menten constant and the maximum reaction rate in PMMA/PPy matrices were of the order of that of pristine polypyrrole. However, in terms of repeated use, the copolymer matrices were superior to polypyrrole.
Subject(s)
Enzymes, Immobilized/metabolism , Glycoside Hydrolases/metabolism , Polymers/metabolism , Polymethyl Methacrylate/metabolism , Pyrroles/metabolism , Thiophenes/metabolism , Electric Conductivity , Electrolysis , Hydrogen-Ion Concentration , Kinetics , Microscopy, Electron, Scanning , Surface Properties , Temperature , beta-FructofuranosidaseABSTRACT
This paper reports a novel approach in the electrode immobilization of an enzyme, invertase, by electrochemical polymerization of pyrrole in the presence of enzyme. The polypyrrole/invertase and polyamide/polypyrrole/invertase electrodes were constructed by the entrapment of enzyme in conducting matrices during electrochemical polymerization of pyrrole. This study involves the preparation and characterization of polypyrrole/invertase and polyamide/polypyrrole/invertase electrodes under conditions compatible with the enzyme. It demonstrates the effects of pH and temperature on the properties of enzyme electrode. Enzyme leakage tests were carried out during reuse number studies. The preparation of enzyme electrodes was done in two different electrolyte/solvent systems. The enzyme serves as a sucrose electrode and retains its activity for several months.
Subject(s)
Enzymes, Immobilized/metabolism , Glycoside Hydrolases/metabolism , Pyrroles/chemistry , Drug Carriers , Electrochemistry , Electrodes/standards , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/standards , Glycoside Hydrolases/chemistry , Glycoside Hydrolases/standards , Hydrogen-Ion Concentration , Microscopy, Electron, Scanning , Nylons/chemistry , Polymers , Sucrose/metabolism , Surface Properties , Temperature , beta-FructofuranosidaseABSTRACT
Electrochemically prepared films of conducting polymers of polypyrrole and polythiophene and their blends with polyamide have been investigated by X-ray photoelectron spectroscopy. In the N1s region of the spectra of films containing polypyrrole the peak corresponding to N(+) at 402.0 eV is separated from that of neutral N. The intensity of the N(+) peak can be correlated with the electrical conductivity of the films and the spectroscopically derived ratio of F/N(+) is close to 4 indicating that one BF(-)(4) dopant ion is incorporated for every oxidized nitrogen center. In the spectra of films of polythiophene and its blends peaks corresponding to S and S(+) can not be resolved but again the F/C ratio correlates with the electrical conductivity.
