title: DNA-wrapped carbon nanotubes as sensitive electrochemical labels in controlled-assembly-mediated signal transduction for the detection of sequence-specific DNA.
abstract: A novel electrochemical strategy that uses DNA-wrapped carbon nanotubes (CNTs) as electrochemical labels is developed for sensitive and selective detection of sequence-specific DNA. The presence of target DNA mediates the formation of a sandwiched complex between the DNA-wrapped CNT and a hairpin DNA capture probe immobilized on magnetic beads. This allows target-selective collection of the CNT labels by magnetic separation and transfer on the electrode surface modified with an insulating self-assembled monolayer (SAM). After treatment with N,N-dimethylformamide, the collected sandwiched complex releases the bare CNTs and facilitates the removal of magnetic beads from the electrode surface. The bare CNTs can then assemble on the SAM-modified electrode surface and mediate efficient electron transfer between the electrode and the electroactive species in the solution with a strong current signal generated. The results indicate that the developed strategy shows a sensitive response to target DNA with a desirable signal gain and a low detection limit of 0.9 pM. This strategy is also demonstrated to provide excellent differentiation of single-base mismatch in target DNA. It is expected that this electrochemical strategy may hold great potential as a novel platform for clinical diagnostics and genetic analysis.
authors.affiliation: Nanomaterials and Chemistry Key Laboratory, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, 325027, P R China. niehuagui@wzu.edu.cn
authors.forename: Huagui
authors.initials: H
authors.lastname: Nie
authors.forename: Zhi
authors.initials: Z
authors.lastname: Yang
authors.forename: Shaoming
authors.initials: S
authors.lastname: Huang
authors.forename: Zhan
authors.initials: Z
authors.lastname: Wu
authors.forename: Hongqi
authors.initials: H
authors.lastname: Wang
authors.forename: Ruqin
authors.initials: R
authors.lastname: Yu
authors.forename: Jianhui
authors.initials: J
authors.lastname: Jiang
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D004126:Dimethylformamide / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D037742:Nanotubes, Carbon / Q000737:chemistry*; D015398:Signal Transduction
chemical_list: D037742:Nanotubes, Carbon; D004126:Dimethylformamide; D004247:DNA