Journal article
Enhanced electrochemical sensitivity of enzyme precipitate coating (EPC)-based glucose oxidase biosensors with increased free CNT loadings
Bioelectrochemistry (Amsterdam, Netherlands), Vol.101, pp.114-119
02/2015
Handle:
https://hdl.handle.net/2376/102267
PMID: 25218216
Abstract
Enzymatic electrodes were fabricated by using three different immobilizations of glucose oxidase (GOx): covalent enzyme attachment (CA), enzyme coating (EC), and enzyme precipitate coating (EPC), here referred to as CA-E, EC-E, and EPC-E, respectively. When additional carbon nanotubes (CNTs) were introduced from 0 to 75wt% for the EPC-E design, its initial biosensor sensitivity was improved from 2.40×10−3 to 16.26×10−3 A∙M−1∙cm−2, while its electron charge transfer rate constant was increased from 0.33 to 1.47s−1. When a fixed ratio of CNTs was added for three different electrode systems, EPC-E showed the best glucose sensitivity and long-term thermal stability. For example, when 75wt% of additional CNTs was added, the initial sensitivity of EPC-E was 16.26×10−3 A∙M−1∙cm−2, while those of EC-E and CA-E were only 6.42×10−3 and 1.18×10−3 A∙M−1∙cm−2, respectively. Furthermore, EPC-E retained 63% of its initial sensitivity after thermal treatment at 40°C over 41days, while EC-E and CA-E showed only 12% and 1% of initial sensitivities, respectively. Consequently, the EPC approach with additional CNTs achieved both high sensitivity and long-term stability, which are required for continuous and accurate glucose monitoring.
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•Enzyme precipitate coatings-carbon nanotubes offer high enzyme loading and stability.•EPC-CNT was entrapped with additional CNTs in Nafion matrix to form enzyme anode.•CNT addition improved the sensitivity from 2.40×10−3 to 16.26×10−3 A∙M−1∙cm−2.•EPC electrode can be employed for continuous glucose monitoring and biofuel cells.
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Details
- Title
- Enhanced electrochemical sensitivity of enzyme precipitate coating (EPC)-based glucose oxidase biosensors with increased free CNT loadings
- Creators
- Jae Hyun Kim - Department of Chemical and Biological Engineering, Korea University, Seoul 136-701, Republic of KoreaSun-Ae Jun - Clean Energy Center, Korea Institute of Science and Technology, Seoul 136-791, Republic of KoreaYongchai Kwon - Graduate School of Energy and Environment, Seoul National University of Science and Technology, Seoul 139-743, Republic of KoreaSu Ha - Department of Chemical Engineering, Washington State University, Pullman, WA 99164, USAByong-In Sang - Department of Chemical Engineering, Hanyang University, Seoul 133-791, Republic of KoreaJungbae Kim - Department of Chemical and Biological Engineering, Korea University, Seoul 136-701, Republic of Korea
- Publication Details
- Bioelectrochemistry (Amsterdam, Netherlands), Vol.101, pp.114-119
- Academic Unit
- Chemical Engineering and Bioengineering, School of
- Publisher
- Elsevier B.V
- Identifiers
- 99900546668801842
- Language
- English
- Resource Type
- Journal article