An investigation of the mechanisms of electronic sensing of protein adsorption on carbon nanotube devices.

Abstract

It has been reported that protein adsorption on single-walled carbon nanotube field effect transistors (FETs) leads to appreciable changes in the electrical conductance of the devices, a phenomenon that can be exploited for label-free detection of biomolecules with a high potential for miniaturization. This work presents an elucidation of the electronic biosensing mechanisms with a newly developed microarray of nanotube "micromat" sensors. Chemical functionalization schemes are devised to block selected components of the devices from protein adsorption, self-assembled monolayers (SAMs) of methoxy(poly(ethylene glycol))thiol (mPEG-SH) on the metal electrodes (Au, Pd) and PEG-containing surfactants on the nanotubes. Extensive characterization reveals that electronic effects occurring at the metal-nanotube contacts due to protein adsorption constitute a more significant contribution to the electronic biosensing signal than adsorption solely along the exposed lengths of the nanotubes.

• Authors: Robert J Chen, Hee Cheul Choi, Sarunya Bangsaruntip, Erhan Yenilmez, Xiaowu Tang, Qian Wang, Ying-Lan Chang, Hongjie Dai
• Journal: Journal of the American Chemical Society (J Am Chem Soc) Vol. 126 Issue 5 Pg. 1563-8 (Feb 11 2004) ISSN: 0002-7863 [Print] United States
• PMID: 14759216 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Nanotubes, Carbon
• Proteins
• Sulfhydryl Compounds
• Polyethylene Glycols
• Palladium
• Gold

Topics

• Adsorption
• Animals
• Biosensing Techniques (methods)
• Cattle
• Gold (chemistry)
• Humans
• Microscopy, Atomic Force
• Nanotubes, Carbon (chemistry)
• Palladium (chemistry)
• Polyethylene Glycols (chemistry)
• Proteins (chemistry)
• Sulfhydryl Compounds (chemistry)