title: Label-free detection of DNA hybridization using pyrene-functionalized single-walled carbon nanotubes: effect of chemical structures of pyrene molecules on DNA sensing performance.
abstract: We investigate the effect of functional groups of pyrene molecules on the electrical sensing performance of single-walled carbon nanotubes (SWNTs) based DNA biosensor, in which pyrenes with three different functional groups of carboxylic acid (Py-COOH), aldehyde (Py-CHO) and amine (Py-NH2) are used as linker molecules to immobilize DNA on the SWNT films. UV/Visible absorption spectra results show that all of the pyrene molecules are successfully immobilized on the SWNT surface via pi-pi stacking interaction. Based on fluorescence analysis, we show that the amide bonding of amine terminated DNA via pyrene containing carboxylic groups is the most efficient to immobilize DNA on the nanotube film. The electrical detection results show that the conductance of Py-COOH modified SWNT film is increased upon DNA immobilization, followed by further increase after hybridization of target DNAs. It indicates that the pyrene molecules with carboxylic acid groups play an important role to achieve highly efficient label-free detection by nondestructive and specific immobilization of DNAs.
authors.affiliation: Department of Chemical and Biomolecular Engineering (BK-21), Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701, Korea.
authors.forename: Youn-Kyoung
authors.initials: YK
authors.lastname: Baek
authors.forename: Dae-Hwan
authors.initials: DH
authors.lastname: Jung
authors.forename: Seung Min
authors.initials: SM
authors.lastname: Yoo
authors.forename: Sunhaera
authors.initials: S
authors.lastname: Shin
authors.forename: Ju-Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Hwan-Jin
authors.initials: HJ
authors.lastname: Jeon
authors.forename: Yang-Kyu
authors.initials: YK
authors.lastname: Choi
authors.forename: Sang Yup
authors.initials: SY
authors.lastname: Lee
authors.forename: Hee-Tae
authors.initials: HT
authors.lastname: Jung
mesh_terms: D004247:DNA / Q000032:analysis* / Q000235:genetics*; D037742:Nanotubes, Carbon; D009693:Nucleic Acid Hybridization; D011721:Pyrenes / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D037742:Nanotubes, Carbon; D011721:Pyrenes; D004247:DNA; C030984:pyrene