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The Application Of Conducting And Non-conducting Polymers In The Glucose Biosensors

Posted on:2005-01-10Degree:MasterType:Thesis
Country:ChinaCandidate:H ChenFull Text:PDF
GTID:2168360125958767Subject:Materials science
Abstract/Summary:PDF Full Text Request
Glucose biosensors were prepared by one-step electrochemical method or electrochemical doping method with poly (m-phenylenediamine) film (PMPD), polyaniline-graphite powder composite film (PGPCF) and Pt-dispersed nano-fibrous PANI film [(Pt/(Nano-fibrous PANI)). The morphology of polymer films and the electrochemical response performance were investigated by scanning electron microscopy (SEM) and electrochemical method. The results show that the morphology of PMPD and PGPCF are porous and netty structure, which possess large specific area and benefit to the immobilization of glucose oxidase (GOD). And PANI films with nano-fibrous structure and Pt microparticles with 50-80 nm diameter dispersed on PANI nano-fiber can be observed from the morphology of Pt/(Nano-fibrous PANI), which has very large specific surface area to the immobilization of GOD and good electrocatalytic activity to the electrooxidation of H202-Furthermore, the influence of electrochemical preparation parameters on the morphology of polymer and the effect of polymer morphology, detecting temperature, potential and pH value of glucose solution on the performance of electrochemical response of enzyme electrode are studied in detail. In order to obtained the optimal porous and netty PMPD film with excellent electrochemical response properties, the synthetic parameters should be controlled at the following conditions: ton/toff, 1:1; pulse frequency, 10Hz; mean current density of PGM,1mA/cm2; GOD concentration, 5g/L.The enzyme electrodes prepared above all show good electrochemical response performance, and the Pt/(Nano-fibrous PANI) enzyme electrode shows the best response performance compared to the other two enzyme electrodes. The effects of conditions for Pt deposition by PGM, Pt loading and PANI thickness on the electrocatalytic activity of Pt/(Nano-fibrous PANI) for H2O2 oxidation have also been researched. And the Pt/(Nano-fibrous PANI) with the optimal electrocatalytic properties for H2O2 oxidation was then used to construct the PMPD-GOD/Pt/ (Nano-fibrous PANI) electrode. The results show the PMPD-GOD/ Pt/(Nano-fibrous PANI) electrode gave a linear response to glucose in the range 2xlO-6 to 12xlO-3 mol/L, the corresponding linearity (R) is more than 0.99. And a fast amperometricresponse time of about 7s (95% of steady-state current) to glucose and good anti-interferent to uric acid or ascorbic acid have also been observed. Furthermore, the PMPD-GOD/Pt/(Nano-fibrous PANI) electrode was applied to determination glucose concentration in serum, and the analytical results provided by the hospital and those determined by using the enzyme electrode agrees closely.Based on the calculating of the kinetic parameters, the maximum response current density ( im ) of the PMPD-GOD, PGPCF-GOD and PMPD-GOD/Pt/ (Nano-fibrous PANI) electrode were 231.4uA/cm\ 357.17uA/cm2 and 917.4uA/cm2, respectively, and the corresponding Michaelis-Menten constant ( K'm ) were 15.33 l(r3mol/L, 16.57 10-3mol/L and 9.34 10-3mol/L, respectively.
Keywords/Search Tags:Poly(m-phenylenediamine), Polyaniline-graphite powder composite film, Nano-fibrous polyaniline film, Pulse galvanostat, Enzyme electrode, Electrochemical response, Sensor
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