Understanding doping effects in biosensing using carbon nanotube network field-effect transistors

作者：Li Jiantong; Zhang Shi Li^*

来源：Physical Review B, 2009, 79(15): 155434.

DOI：10.1103/PhysRevB.79.155434

• biosensors
• carbon nanotubes
• DNA
• doping
• field effect transistors
• molecular biophysics
• nanocontacts
• nanotube devices
• percolation
• proteins

Systematic theoretical studies based on a comprehensive heterogeneous stick percolation model are performed to gain insights into the essence of doping effects in electrical sensing of biomolecules, such as proteins and DNA fragments, using carbon nanotube network field-effect transistors (CNNFETs). The present work demonstrates that the electrical response to doping of CNNFETs is primarily caused by conductance change at the electrode-nanotube contacts, in contrast to that in the channel as assumed previously. However, the presence of intertube junctions in the channel could reduce the sensitivity of CNNFET-based biosensors and is partially responsible for the experimentally observed channel-length dependent sensitivity.

• 出版日期2009-4