An investigation of the mechanisms of electronic sensing of protein adsorption on carbon nanotube devices.
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.
Chen
Robert J
RJ
Department of Chemistry, Stanford University, Stanford, California 94305, USA.
Choi
Hee Cheul
HC
Bangsaruntip
Sarunya
S
Yenilmez
Erhan
E
Tang
Xiaowu
X
Wang
Qian
Q
Chang
Ying-Lan
YL
Dai
Hongjie
H
D000327:Adsorption; D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002417:Cattle; D006046:Gold / Q000737:chemistry; D006801:Humans; D018625:Microscopy, Atomic Force; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011506:Proteins / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry
D037742:Nanotubes, Carbon; D011506:Proteins; D013438:Sulfhydryl Compounds; D011092:Polyethylene Glycols; D010165:Palladium; D006046:Gold