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Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.14/168717
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- Title
- A Label-free electrochemical DNA biosensor based on a Zr(IV)-coordinated DNA duplex immobilised on a carbon nanofibre|chitosan layer
- Related
- Analytical and bioanalytical chemistry, Vol. 402, No. 9, (2012), p.2817-2826
- DOI
- 10.1007/s00216-012-5733-0
- Publisher
- Springer Verlag
- Date
- 2012
- Author/Creator
- Wipawakarn, Patoommarn
- Author/Creator
- Ju, Huangxian
- Author/Creator
- Wong, Danny K. Y
- Description
- A label-free electrochemical biosensor for detecting DNA hybridisation was developed by monitoring the change in the voltammetric activity of ferrocenecarboxylic acid at the biosensor-solution interface. The biosensor was constructed by initially immobilising on a glassy carbon electrode an anchoring layer consisting of chitosan, carboxyl group functionalised carbon nanofibres and glutaraldehye. Chitosan acted as an adhering agent and carbon nanofibres were strategically used to provide a large surface area with binding points for DNA immobilisation, while glutaraldehye was a linker for DNA probes on the electrode surface. Based on a two-factorial design, cyclic voltammetry of [Fe(CN) 6] 3-/4- was performed to optimise the composition of the anchoring layer. Next, a 17-base pair DNA probe was attached to the anchoring layer, followed by its complementary target. Zr(IV) ion, known to exhibit affinity for oxygen-containing electroactive markers, for example, ferrocenecarboxylic acid, was then coordinated in the DNA duplex. In this way, ferrocenecarboxylic acid was attracted towards the biosensor for oxidation. A change in the voltammetric oxidation current of ferrocenecarboxylic acid pre- and post-hybridisation was used to provide an indication of hybridisation. A linear dynamic range between 0.5 and 40 nM and a detection limit of 88 pM of DNA target were then achieved. In addition, the biosensor exhibited good selectivity, repeatability and stability for the determination of DNA sequences.
- Description
- 10 page(s)
- Subject Keyword
- 030100 Analytical Chemistry
- Subject Keyword
- Carbon nanofibre
- Subject Keyword
- Chitosan
- Subject Keyword
- Electrochemical DNA sensor
- Subject Keyword
- Label-free detection
- Subject Keyword
- Zr(IV)-coordinated DNA duplex
- Resource Type
- journal article
- Organisation
- Macquarie University. Department of Chemistry and Biomolecular Sciences
- Identifier
- http://hdl.handle.net/1959.14/168717
- Identifier
- mq:19278
- Identifier
- ISSN:1618-2642
- Identifier
- mq-rm-2011006194
- Identifier
- mq_res-ext-2-s2.0-84858706678
- Language
- eng
- Reviewed
Macquarie University ResearchOnline
