title: 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.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Chen
authors.forename: Hee Cheul
authors.initials: HC
authors.lastname: Choi
authors.forename: Sarunya
authors.initials: S
authors.lastname: Bangsaruntip
authors.forename: Erhan
authors.initials: E
authors.lastname: Yenilmez
authors.forename: Xiaowu
authors.initials: X
authors.lastname: Tang
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.forename: Ying-Lan
authors.initials: YL
authors.lastname: Chang
authors.forename: Hongjie
authors.initials: H
authors.lastname: Dai
mesh_terms: 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
chemical_list: D037742:Nanotubes, Carbon; D011506:Proteins; D013438:Sulfhydryl Compounds; D011092:Polyethylene Glycols; D010165:Palladium; D006046:Gold