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| Author(s): |
Fernanda Cristina Pena Ferreira Sales
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Carlos. |
| Institution: | Universidade de São Paulo (USP). Instituto de Química de São Carlos (IQSC/BT) |
| Defense date: | 2017-11-07 |
| Examining board members: |
Frank Nelson Crespilho;
Filipe Camargo Dalmatti Alves Lima;
Wilson Tadeu Lopes da Silva
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| Advisor: | Frank Nelson Crespilho |
| Abstract | |
Enzymatic biofuel cells (BFCs) are electrochemical devices that convert chemical energy into electrical energy using enzymes as biocatalysts. When miniaturized, BFCs can be implanted in vertebrate and invertebrate animals and, their use to produce electrical energy to feed biomedical microdevices and micro-sensors in small insects can be observed. However, it is still challenging to obtain implantable and miniaturized BFCs, with sufficient power (tens of microwatts) to power electronic microcircuits in a stable and long-term manner. In view of the above, this PhD thesis presents a study of the electrochemical properties of enzymatic electrodes, aiming to use them in miniaturized and implantable glucose/O2 BFCs. In order to obtain a reduction in O2 and oxidation of glucose, flexible carbon fibers (FCFs) modified with bilirubin oxidase (BOx) enzymes in the cathode and glucose dehydrogenase (GDh) at the anode, respectively, were used. The results show that FCFs previously submitted to a chemical treatment of oxidation with potassium permanganate and, subsequently, electropolymerization of the neutral red mediator produce stable and robust bioanodes. These electrodes, combined with biocathodes consisting of FCFs in the absence of redox mediators, were used in miniaturized BFCs, which were implanted in Atta sexdens rubrupilosa ant species. The BFC maximum power source, operating in vivo, was 13.5 ± 3.8 μW cm-2 at 190 ± 58.9 mV, with a maximum current of 143 ± 40.2 μA cm-2 and the open circuit voltage was 260 ± 99.6 mV. Although these values can be optimized, this research shows that the flexibility of the FCF, the presence of a polymer electron mediator on the anode, using the chemical treatment of oxidation with potassium permanganate of the fibers and electrode miniaturization are important elements, which can be considered in the development of implantable biofuels. (AU) | |
| FAPESP's process: | 13/07829-0 - Evaluation of Electrochemical Properties of Glucose/O2 Implantable Biofuel Cell |
| Grantee: | Fernanda Cristina Pena Ferreira Sales |
| Support Opportunities: | Scholarships in Brazil - Doctorate |