Preparation of Redox Polymer Nanocomposites for Application in Biosensors and Biofuel Cells
Date Issued
2014
Date
2014
Author(s)
Wang, Jen-Yuan
Abstract
In this dissertation, we synthesized redox polymers and polymer composites for the electrode modification. Then, we applied these redox polymers to the biosensors and biofuel cells (BFCs), in order to improve the sensitivity and selectivity of the biosensor or the power output of the BFCs.
In the first part (in Chapter 3), poly(methylene blue) (PMB) was grown on the screen–printed carbon paste electrode (SPCE), which is modified with multi–walled carbon nanotubes (MWCNTs), by electrodeposition. We find that MWCNTs are capable of significantly increasing the deposition amount and the surface area of PMB. In addition, the electron transfer rate and also be improved by incorporating MWCNTs. For the applications, PMB/MWCNTs/SPCE was used as the Nicotinamide adenine dinucleotide (reduced form, NADH) sensor, and the electrocatalysis of NADH oxidation was also investigated. After combined with glucose dehydrogenase (GDH), this material could be used for the bioanode of the glucose bio–battery’s prototype. The choice of the iodide/tri–iodide redox couple eliminates the dependence of oxygen for this bio–battery.
In the second part (in Chapter 4), a redox hydrogel polyhydroquinone–chitosan (PHQ–CS) was prepared by chemical polymerization and used to entrap the GOD and the PHQ in the matrix of chitosan. In addition, the PHQ–CS could work as the electron mediator of GOx, and thus the PHQ–CS could be applied to the fabrication of the bioanodes for the glucose BFCs system. To further improve the electrocatalytic efficiency of bioanode, carboxyl–functionalized MWCNTs were introduced during the preparation of the redox PHQ–CS hydrogel.
In the third part (in Chapter 5), the redox polymer nanobeads containing branched polyethylenimine (BPEI) and ferrocene (Fc) redox mediators was prepared. The size of the redox polymer nanobeads would be affect by different conditions of the fabrication process. With good hydrophilicity, the BPEI–Fc nanobeads can form a well–dispersed aqueous solution. Under the neutral pH condition, glucose oxidase (GOx) is negatively charged and BPEI–Fc bears positive charges. Thus, GOx and BPEI–Fc can be blended well by electrostatic affinity. Besides, with lower chain flexibility the BPEI nanobeads can maintain their morphology and form nanocomposites with other materials. For instance, after further incorporation of conductive poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS), we fabricate BPEI–Fc/PEDOT:PSS/GOx/SPCE that shows high glucose oxidation currents.
The fourth part (in Chapter 6), poly(3–aminophenylboronic acid) (PAPBA), which not only possesses the redox activity but also the boronic acid functionality, was prepared and used for the development of an amperometric Glycated hemoglobin (HbA1c) sensor. When the HbA1c was covalently bounded to the conducting polymer film, the current response can represent the amount of the HbA1c adsorbed. Therefore, the HbA1c concentration in the bulk solution can be estimated. To further investigate the mechanism of the HbA1c sensor, in situ study of the mass change of the PAPBA was also carried out by using an electrochemical quartz crystal microbalance (EQCM) experiment.
Subjects
葡萄糖感測器
葡萄糖生物燃料電池
糖化血色素感測器
多壁奈米碳管
聚(3,4–並乙二氧基噻吩)–聚(苯乙烯磺酸)
聚氨基苯基硼酸
聚對苯二酚
聚亞甲基藍
氧化還原高分子
Type
thesis
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