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 AM-1cm-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 AM-1cm-2, while those of EC-E and CA-E were only 6.42×10-3 and 1.18×10-3 AM-1cm-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.
| Original language | English |
|---|---|
| Pages (from-to) | 114-119 |
| Number of pages | 6 |
| Journal | Bioelectrochemistry |
| Volume | 101 |
| DOIs | |
| Publication status | Published - 2015 Feb 1 |
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Keywords
- Carbon nanotubes
- Electron generation and transfer
- Enzymatic glucose sensors
- Enzyme precipitate coating
- Glucose oxidase
ASJC Scopus subject areas
- Biophysics
- Electrochemistry
- Physical and Theoretical Chemistry
Cite this
Enhanced electrochemical sensitivity of enzyme precipitate coating (EPC)-based glucose oxidase biosensors with increased free CNT loadings. / Kim, Jae Hyun; Jun, Sun Ae; Kwon, Yongchai; Ha, Su; Sang, Byong In; Kim, Jungbae.
In: Bioelectrochemistry, Vol. 101, 01.02.2015, p. 114-119.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Enhanced electrochemical sensitivity of enzyme precipitate coating (EPC)-based glucose oxidase biosensors with increased free CNT loadings
AU - Kim, Jae Hyun
AU - Jun, Sun Ae
AU - Kwon, Yongchai
AU - Ha, Su
AU - Sang, Byong In
AU - Kim, Jungbae
PY - 2015/2/1
Y1 - 2015/2/1
N2 - 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 AM-1cm-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 AM-1cm-2, while those of EC-E and CA-E were only 6.42×10-3 and 1.18×10-3 AM-1cm-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.
AB - 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 AM-1cm-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 AM-1cm-2, while those of EC-E and CA-E were only 6.42×10-3 and 1.18×10-3 AM-1cm-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.
KW - Carbon nanotubes
KW - Electron generation and transfer
KW - Enzymatic glucose sensors
KW - Enzyme precipitate coating
KW - Glucose oxidase
UR - http://www.scopus.com/inward/record.url?scp=84949116934&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84949116934&partnerID=8YFLogxK
U2 - 10.1016/j.bioelechem.2014.08.017
DO - 10.1016/j.bioelechem.2014.08.017
M3 - Article
VL - 101
SP - 114
EP - 119
JO - Bioelectrochemistry
JF - Bioelectrochemistry
SN - 1567-5394
ER -