An Investigation of the Mechanisms of Electronic Sensing of Protein Adsorption on Carbon Nanotube Devices

作者：Robert J. Chen, Hee Cheul Choi, Sarunya Bangsaruntip, Erhan Yenilmez, Xiaowu Tang, Qian Wang, Ying‐Lan Chang, Hongjie Dai · 发表于：Journal of the American Chemical Society · 年份：2004 · DOI：10.1021/ja038702m · 被引用次数：519 · 研究领域：Carbon Nanotubes in Composites、Mechanical and Optical Resonators、Nanotechnology research and applications

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.