Electronic transport characteristics of a single wall carbon nanotube field effect transistor wrapped with deoxyribonucleic acid molecules

A SWCNT-FET device wrapped with DNA molecules was fabricated and the electronic transport properties were investigated. The gate modulated current-voltage characteristics of a bare SWCNT-FET device showed a p-type conduction behavior, which was consistent with generally characteristics in previous studies. However, the characteristics of the DNA-wrapped SWCNT-FET showed clear staircase structures. In addition, the conduction type was changed from p-type to n-type and the transconductance of the DNA-wrapped SWCNT-FET became smaller than that of the bare SWCNT-FET. All these observations provided the evidences of DNA wrapping on the surface of SWCNTs. Especially, the observed type conversion was interpreted as a result of oxygen transport from the surface of SWCNT to DNA molecules across the SWCNT-DNA interface