title: Modulation of molecular hybridization and charge screening in a carbon nanotube network channel using the electrical pulse method.
abstract: In this paper, we investigate the effect of electrical pulse bias on DNA hybridization events in a biosensor platform, using a Carbon Nanotube Network (CNN) and Gold Nano Particles (GNP) as an electrical channel. The scheme provides both hybridization rate enhancement of bio molecules, and electrical measurement in a transient state to avoid the charge screening effect, thereby significantly improving the sensitivity. As an example, the probe DNA molecules oscillate with pulse trains, resulting in the enhancement of DNA hybridization efficiency, and accordingly of the sensor performances in Tris-EDTA (TE) buffer solution, by as much as over three times, compared to the non-biasing conditions. More importantly, a wide dynamic range of 10(6) (target-DNA concentration from 5 pM to 5 μM) is achieved in human serum. In addition, the pulse biasing method enables one to obtain the conductance change, before the ions within the Electrical Double Layer (EDL) are redistributed, to avoid the charge screening effect, leading to an additional sensitivity enhancement.
authors.affiliation: Department of Electrical and Computer Engineering, Seoul National University, Seoul 151-744, Republic of Korea.
authors.forename: Jun-Myung
authors.initials: JM
authors.lastname: Woo
authors.forename: Seok Hyang
authors.initials: SH
authors.lastname: Kim
authors.forename: Honnggu
authors.initials: H
authors.lastname: Chun
authors.forename: Sung Jae
authors.initials: SJ
authors.lastname: Kim
authors.forename: Jinhong
authors.initials: J
authors.lastname: Ahn
authors.forename: Young June
authors.initials: YJ
authors.lastname: Park
mesh_terms: D015374:Biosensing Techniques; D004247:DNA / Q000097:blood*; D015342:DNA Probes / Q000737:chemistry / Q000378:metabolism; D004560:Electricity; D055664:Electrochemical Techniques; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D006801:Humans; D008297:Male; D053768:Metal Nanoparticles / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009693:Nucleic Acid Hybridization; D010316:Particle Size; D013696:Temperature
chemical_list: D015342:DNA Probes; D037742:Nanotubes, Carbon; D006046:Gold; D004247:DNA