The acid-base properties of carboxylated CNT and the design of CNTFET biosensor

H.J. Kwon, J-M Woo, J. Lim, S.H. Kim, Y.J. Park
Seoul National University, KR

Keywords: carbon nanotube, dynamic measurement, pH of solution

Summary:

We observed the sign of the two responses from carbon nanotube field effect transistor (CNTFET) in aqueous solution by means of dynamic measurements. Two types of surface group, the hydroxyl and the carboxyl group of sensor surface are amphoteric materials depending on the pH. After blocking of COOH group on the CNT surface, CNT characteristics become insensitive to pH condition. This result brings benefits to reliable operation and optimal design of CNTFET sensor