Abstract
Boron-doped diamond electrodes covered with a nanostructured Pt nanoparticle-polyaniline composite have been fabricated and employed as sensitive amperometric sensors with low detection limit. A highly conductive boron-doped diamond thin film (BDD) was prepared by chemical vapor deposition, and its morphology was characterized by scanning electron microscopy and transmission electron microscopy. The nanostructured composite layer was grown on the BDD electrode by electrochemical deposition of polyaniline and Pt nanoparticles. Glucose oxidase (GOx) was then adsorptively immobilized on the modified BDD electrode. The biosensor displays a large surface area, high catalytic activity of the Pt nanoparticles, efficient electron mediation through the conducting polymer, and low background current of the electrode. The biosensor exhibits an excellent response to glucose, with a broad linear range from 5. 9 μM to 0. 51 mM, a sensitivity of 5. 5 μA·mM-1, a correlation coefficient (R) of 0. 9947, and a detection limit of 0. 10 μM. The apparent Michaelis-Menten constant (KMapp) and the maximum current density of the electrode are 4. 1 mM and 0. 021 mA, respectively. This suggests that the immobilized GOx possesses a higher affinity for glucose at the lower KMapp, and that the enzymatic reaction rate constitutes the rate-limiting step of the response.
Original language | English |
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Pages (from-to) | 249-255 |
Number of pages | 7 |
Journal | Microchimica Acta |
Volume | 171 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2010 Dec |
Bibliographical note
Funding Information:This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2010-000029) and by the second stage of the Brain Korea 21 Project in 2010. D.W. acknowledges the support by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2010-0015035).
Keywords
- Boron-doped diamond
- Effective surface area
- Electrochemical sensor
- Glucose sensor
- Polyaniline
- Pt nanoparticles
ASJC Scopus subject areas
- Analytical Chemistry