Surface functionalization of multiwalled carbon nanotube for biosensor device application

CNT has been widely known for its excellent electrical and thermal conductivities. However, these desirable properties are limited for application due to the inertness of CNT. This work emphasize on a simple and practical method of MWCNT functionalization by sonication in mild acid condition. A mixture of nitric acid and sulfuric acid in ratio of 1:3 were demonstrated as an oxidizing agent to introduce carboxyl functional group on MWCNTs surface. The chemical bonding and surface morphology were examined using FTIR and SEM respectively and indicates a successful functionalization of carboxyl functional group. This work will be further developed for application of functionalized MWCNT for biosensor device.