The field effect transistor (FET) made of carbon nanotube (CNT) can be used as sensor due to their extreme sensitivity to local chemical environments. Glutamate is the principal excitatory neurotransmitter in the brain, and its excessive release plays a key role in neuronal death associated with a wide range of neuronal disorders. In order to detect glutamate, we immobilized glutamate oxidase (GLOD) on CNT network junctions by non-covalent functionalized method to preserve their electronic characteristics. After immobilizing GLOD on CNT junctions, the excess reactive groups of linker molecule remaining on the CNT surface was deactivated and blocked by ethanolamine. The electrical property of GLOD-immobilized CNT network transistor was characterized as source-drain current that depended on liquid gate voltage. From the changes of Isd vs. Vg plot about CNT network transistor before and after the immobilization of GLOD, we confirmed that GLOD immobilization decreased the conductance of CNT network junctions, regardless of the sign on the net charge in the protein. The real time electronic response of probe-type CNT network transistors immobilized by GLOD was conducted with glutamate standard solution in vitro and 11 vessel rat occlusion model in vivo. The ultrahigh sensitivity, selectivity, and fast response time of GLOD-immobilized CNT network transistor could provide great potential for real time electronic detection in the extracellular glutamate level of the brain.
Journal: TechConnect Briefs
Volume: 2, Nanotechnology 2008: Life Sciences, Medicine & Bio Materials – Technical Proceedings of the 2008 NSTI Nanotechnology Conference and Trade Show, Volume 2
Published: June 1, 2008
Pages: 646 - 648
Industry sectors: Medical & Biotech | Sensors, MEMS, Electronics
Topic: Chemical, Physical & Bio-Sensors