Single-stranded dna as a dual functioning biomolecule in graphene composite supercapacitor /
Yasin M. Y. Albarqouni
- xviii, 97 pages : illustrations (some color) ; 30 cm. + 1 CD-ROM
Faculty of Industrial Sciences and Technology
Thesis (Master of Science ) -- Universiti Malaysia Pahang – 2021
Includes bibliographical references
The enrichment of DNA’s chemistry endows DNA with a high level of interest in bioelectronics applications. This research investigates the charge storage capability and mechanism for the synthesis of GO/DNA bio-composite aiming to develop a new type of supercapacitors based on biomaterial. To this end, a sequential success of material synthesis confirmed, starting with successful isolation of DNA from saccharomyces cerevisiae from broth culture extended to successful oxidation of graphite flakes using the modified Hummer’s method to further develop a one-step reduction and functionalisation of graphene oxide (GO) with different DNA forms. The composites physiochemical properties investigated with spectroscopic techniques including UV-Vis, Fourier transform infrared (FTIR), X-ray diffraction (XRD), Raman shift, and fluorescent spectroscopies (FL). In addition, surface morphology after the reduction observed by employing FESEM. Cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) techniques employed in threeelectrode configurations to study the electrochemical characteristics of the pure GO and the fabricated composites including rGO/ssDNA and GO/dsDNA electrodes in 1 M KOH. rGO/ssDNA working electrode. All of the mentioned techniques verify the reduction of GO in the presence of ssDNA as well as the functionalization of both forms of DNA including double-stranded DNA (dsDNA) and single-stranded DNA (ssDNA) on GO. The easily oxidized guanine nucleic acid acts as a proton pump that reduces oxygen functionalities. All electrochemical investigations confirmed the electric double-layer capacitance (EDLC) effect for pure GO and synthesized composites. It is worth mentioning that the rGO/ssDNA composite elucidated the highest EDLC effect compared to GO and GO/dsDNA composite. Specific capacitance for rGO/ssDNA electrode is found to elucidates approximately 20-folds higher capacitance compared to other electrodes with 226 F g-1at a current density of 0.4 A g-1in 1 M KOH. Furthermore, rGO/ssDNA showed an advancement electrochemical long-term stability of about 92.8% after 10000 cycles in the aqueous basic electrolyte is also reported. The work comes with a successful use of DNA as a reducing agent and conductive biomolecule in graphene composite supercapacitor applications .
THE0009194(Local)
Faculty of Industrial Sciences and Technology--Dissertations