DNA-FET using carbon nanotube electrodes

We demonstrate DNA field effect transistor (DNA-FET) using multiwalled carbon nanotube (MWNT) as nano-structural source and drain electrodes. The MWNT electrodes have been fabricated by focused ion-beam bombardment (FIBB). A very short channel, approximately 50 nm, was easily formed between the severed MWNT. The current-voltage (I-V) characteristics of DNA molecules between the MWNT electrodes showed hopping transport property. We have also measured the gate-voltage dependence in the I-V characteristics and found that poly DNA molecules exhibits p-type conduction. The transport of DNA-FET can be explained by two hopping lengths which depend on the range of the source-drain bias voltages