Plasma thiol-functionalized carbon nanotubes decorated with gold nanoparticles for glucose biosensor

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• 作者：Masoud Vesali-Naseh ; Yadollah Mortazavi ; Abbas Ali Khodadadi ; Pourya Parsaeian ; Ali Akbar Moosavi-Movahedi
• 关键词：Plasma functionalization ; Thiol groups ; CNTs ; Glucose biosensor
• 刊名：Sensors and Actuators B: Chemical
• 出版年：2013
• 出版时间：November, 2013
• 年：2013
• 卷：188
• 期：Complete
• 页码：488-495
• 全文大小：2105 K

文摘

For the first time, MWCNTs were thiol functionalized using dielectric barrier discharge plasma in the presence of H₂S/He at room temperature and atmospheric pressure. At the optimum plasma conditions, maximum amount of 0.57 wt. % thiol groups was formed on the surface of MWCNTs. The deposition-precipitation method was used to decorate MWCNTs with Au-nanoparticles. TEM, FE-SEM, FTIR, Raman, Ellman reagent method, XRD and cyclic voltametry were used to characterize the samples.

A glucose biosensor was fabricated by immobilizing glucose oxidase (GOx) on the Au/MWCNTs hybrid. The redox process of the GOx/Au/MWCNTs hybrid electrode was shown to be reversible and surface-controlled process in 0.1 M phosphate buffer solution at pH 7.0. The charge transfer coefficient and charge transfer rate constant for electron transfer between GOx and the electrode surface were calculated as 0.48 and 1.13 s^?1, respectively. The GOx/Au/MWCNT-modified electrode exhibited a linear behavior in the range of 0.4-4.0 mM glucose with detection limit of 3.0 ¦ÌM and sensitivity of 23.1 ¦ÌA/mM cm². The modified electrode retained more than 58 % of its initial faradic current value after 50 days.