Cyclic voltammetric and electrical impedance spectroscopy studies of graphene- and conductive polymer–based enzyme electrodes
Screen-printed carbon electrodes (SPCEs), modified with graphene oxide and poly(3,4-ethylenedioxythiophene):polystyrenesulfonic acid (GO-PEDOT:PSS/SPCEs), and SPCEs modified with partially reduced GO and PEDOT:PSS (prGO-PEDOT:PSS/SPCEs) were studied for electrochemical transduction. Randles-Sevcik a...
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Universiti Tun Hussein Onn Malaysia
2019
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| Online Access: | http://irep.iium.edu.my/74856/ http://irep.iium.edu.my/74856/1/74856_Cyclic%20Voltammetric%20and%20Electrical%20Impedance.pdf http://irep.iium.edu.my/74856/2/74856_Cyclic%20Voltammetric%20and%20Electrical%20Impedance_WOS.pdf http://irep.iium.edu.my/74856/13/74856_Cyclic%20voltammetric%20and%20electrical%20impedance%20spectroscopy%20studies%20of%20graphene-%20and%20conductive%20polymer-based%20enzyme%20electrodes_Scopus.pdf |
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| author | Ismail, Nur Alya Batrisya Ramli, Nurul Izzati Abd-Wahab, Firdaus Wan Salim, Wan Wardatul Amani |
| author_facet | Ismail, Nur Alya Batrisya Ramli, Nurul Izzati Abd-Wahab, Firdaus Wan Salim, Wan Wardatul Amani |
| author_sort | Ismail, Nur Alya Batrisya |
| building | IIUM Repository |
| collection | Online Access |
| description | Screen-printed carbon electrodes (SPCEs), modified with graphene oxide and poly(3,4-ethylenedioxythiophene):polystyrenesulfonic acid (GO-PEDOT:PSS/SPCEs), and SPCEs modified with partially reduced GO and PEDOT:PSS (prGO-PEDOT:PSS/SPCEs) were studied for electrochemical transduction. Randles-Sevcik analysis showed that the prGO-PEDOT:PSS/SPCE has a higher effective surface area of 219.3 μm2 in comparison to the unreduced GO-PEDOT:PSS/SPCE (87.0 μm2) and the bare SPCE (71.7 μm2). Using electrical impedance spectroscopy (EIS), we determined that the prGO-PEDOT:PSS/SPCE has a lower charge-transfer resistance (Rct) of 163.82 Ω in comparison to the GO-PEDOT:PSS/SPCE (427.87 Ω) and the bare SPCE (13.31 kΩ). Glucose oxidase (GOx) was immobilized on all electrode types, including GO/SPCE as additional control and tested with low (0.2 mM), intermediate (0.6 mM), and high (1 mM) glucose concentrations. GOx/GO/SPCEs showed the largest change in anodic peak current (Ipa), 8.5, 7.5 and 4.9 μA for low, intermediate, and high glucose concentrations, respectively. Interestingly, GOx/prGO-PEDOT:PSS/SPCEs have no change in both anodic and cathodic peak current, although they exhibit better redox capability, while GOx/SPCEs have very low Ipa. The results show that the high effective surface area and low charge-transfer resistance (Rct) of prGO-PEDOT:PSS/SPCEs do not necessarily result in a sensitive glucose sensor in cases where immobilization of enzymes on the material can affect electron transfer. |
| first_indexed | 2025-11-14T17:34:14Z |
| format | Article |
| id | iium-74856 |
| institution | International Islamic University Malaysia |
| institution_category | Local University |
| language | English English English |
| last_indexed | 2025-11-14T17:34:14Z |
| publishDate | 2019 |
| publisher | Universiti Tun Hussein Onn Malaysia |
| recordtype | eprints |
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| spelling | iium-748562020-03-02T02:04:53Z http://irep.iium.edu.my/74856/ Cyclic voltammetric and electrical impedance spectroscopy studies of graphene- and conductive polymer–based enzyme electrodes Ismail, Nur Alya Batrisya Ramli, Nurul Izzati Abd-Wahab, Firdaus Wan Salim, Wan Wardatul Amani QD Chemistry TP155 Chemical engineering TP248.13 Biotechnology Screen-printed carbon electrodes (SPCEs), modified with graphene oxide and poly(3,4-ethylenedioxythiophene):polystyrenesulfonic acid (GO-PEDOT:PSS/SPCEs), and SPCEs modified with partially reduced GO and PEDOT:PSS (prGO-PEDOT:PSS/SPCEs) were studied for electrochemical transduction. Randles-Sevcik analysis showed that the prGO-PEDOT:PSS/SPCE has a higher effective surface area of 219.3 μm2 in comparison to the unreduced GO-PEDOT:PSS/SPCE (87.0 μm2) and the bare SPCE (71.7 μm2). Using electrical impedance spectroscopy (EIS), we determined that the prGO-PEDOT:PSS/SPCE has a lower charge-transfer resistance (Rct) of 163.82 Ω in comparison to the GO-PEDOT:PSS/SPCE (427.87 Ω) and the bare SPCE (13.31 kΩ). Glucose oxidase (GOx) was immobilized on all electrode types, including GO/SPCE as additional control and tested with low (0.2 mM), intermediate (0.6 mM), and high (1 mM) glucose concentrations. GOx/GO/SPCEs showed the largest change in anodic peak current (Ipa), 8.5, 7.5 and 4.9 μA for low, intermediate, and high glucose concentrations, respectively. Interestingly, GOx/prGO-PEDOT:PSS/SPCEs have no change in both anodic and cathodic peak current, although they exhibit better redox capability, while GOx/SPCEs have very low Ipa. The results show that the high effective surface area and low charge-transfer resistance (Rct) of prGO-PEDOT:PSS/SPCEs do not necessarily result in a sensitive glucose sensor in cases where immobilization of enzymes on the material can affect electron transfer. Universiti Tun Hussein Onn Malaysia 2019-09 Article PeerReviewed application/pdf en http://irep.iium.edu.my/74856/1/74856_Cyclic%20Voltammetric%20and%20Electrical%20Impedance.pdf application/pdf en http://irep.iium.edu.my/74856/2/74856_Cyclic%20Voltammetric%20and%20Electrical%20Impedance_WOS.pdf application/pdf en http://irep.iium.edu.my/74856/13/74856_Cyclic%20voltammetric%20and%20electrical%20impedance%20spectroscopy%20studies%20of%20graphene-%20and%20conductive%20polymer-based%20enzyme%20electrodes_Scopus.pdf Ismail, Nur Alya Batrisya and Ramli, Nurul Izzati and Abd-Wahab, Firdaus and Wan Salim, Wan Wardatul Amani (2019) Cyclic voltammetric and electrical impedance spectroscopy studies of graphene- and conductive polymer–based enzyme electrodes. International Journal of Integrated Engineering, 11 (3). pp. 70-80. ISSN 2229-838X E-ISSN 2600-7916 https://publisher.uthm.edu.my/ojs/index.php/ijie/article/view/4541/2943 |
| spellingShingle | QD Chemistry TP155 Chemical engineering TP248.13 Biotechnology Ismail, Nur Alya Batrisya Ramli, Nurul Izzati Abd-Wahab, Firdaus Wan Salim, Wan Wardatul Amani Cyclic voltammetric and electrical impedance spectroscopy studies of graphene- and conductive polymer–based enzyme electrodes |
| title | Cyclic voltammetric and electrical impedance spectroscopy studies of graphene- and conductive polymer–based enzyme electrodes |
| title_full | Cyclic voltammetric and electrical impedance spectroscopy studies of graphene- and conductive polymer–based enzyme electrodes |
| title_fullStr | Cyclic voltammetric and electrical impedance spectroscopy studies of graphene- and conductive polymer–based enzyme electrodes |
| title_full_unstemmed | Cyclic voltammetric and electrical impedance spectroscopy studies of graphene- and conductive polymer–based enzyme electrodes |
| title_short | Cyclic voltammetric and electrical impedance spectroscopy studies of graphene- and conductive polymer–based enzyme electrodes |
| title_sort | cyclic voltammetric and electrical impedance spectroscopy studies of graphene- and conductive polymer–based enzyme electrodes |
| topic | QD Chemistry TP155 Chemical engineering TP248.13 Biotechnology |
| url | http://irep.iium.edu.my/74856/ http://irep.iium.edu.my/74856/ http://irep.iium.edu.my/74856/1/74856_Cyclic%20Voltammetric%20and%20Electrical%20Impedance.pdf http://irep.iium.edu.my/74856/2/74856_Cyclic%20Voltammetric%20and%20Electrical%20Impedance_WOS.pdf http://irep.iium.edu.my/74856/13/74856_Cyclic%20voltammetric%20and%20electrical%20impedance%20spectroscopy%20studies%20of%20graphene-%20and%20conductive%20polymer-based%20enzyme%20electrodes_Scopus.pdf |