Electronically monitoring biological interactions with carbon nanotube field-effect transistors

The year 2008 marks the 10th anniversary of the carbon nanotube field-effect transistor (NTFET). In the past decade a vast amount of effort has been placed on the development of NTFET based sensors for the detection of both chemical and biological species. Towards this end, NTFETs show great promise because of their extreme environmental sensitivity, small size, and ultra-low power requirements. Despite the great progress NTFETs have shown in the field of biological sensing, debate still exists over the mechanistic origins underlying the electronic response of NTFET devices, specifically whether analyte species interact with the carbon nanotube conduction channel or if interaction with the NTFET electrodes actually triggers device response. In this tutorial review, we describe the fabrication of NTFET devices, and detail several reports that illustrate recent advances in biological detection using NTFET devices, while highlighting the suggested mechanisms explaining the device response to analyte species. In doing this we hope to show that NTFET technology has the potential for low-cost and portable bioanalytical platforms.