title: Ultrasensitive electrogenerated chemiluminescence detection of DNA hybridization using carbon-nanotubes loaded with tris(2,2'-bipyridyl) ruthenium derivative tags.
abstract: An ultrasensitive electrogenerated chemiluminescence (ECL) detection method of DNA hybridization based on single-walled carbon-nanotubes (SWNT) carrying a large number of ruthenium complex tags was developed. The probe single strand DNA (ss-DNA) and ruthenium complex were loaded at SWNT, which was taken as an ECL probe. When the capture ss-DNA with a thiol group was self-assembled onto the surface of gold electrode, and then hybridized with target ss-DNA and further hybridized with the ECL probe to form DNA sandwich conjugate, a strong ECL response was electrochemically generated. The ECL intensity was linearly related to the concentration of perfect-matched target ss-DNA in the range from 2.4x10(-14) to 1.7x10(-12)M with a detection limit of 9.0x10(-15)M. The ECL signal difference permitted to discriminate the perfect-matched target ss-DNA and two-base-mismatched ss-DNA. This work demonstrates that SWNT can provide an amplification platform for carrying a large number of ECL probe and thus resulting in an ultrasensitive ECL detection of DNA hybridization.
authors.affiliation: Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi'an 710062, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Honglan
authors.initials: H
authors.lastname: Qi
authors.forename: Fang
authors.initials: F
authors.lastname: Fang
authors.forename: Chengxiao
authors.initials: C
authors.lastname: Zhang