- Title
- Electrochemical detection of short DNA sequences related to the Escherichia coli pathogen using a zirconia-modified screen-printed DNA biosensor
- Creator
- Zuo, Shao-Hua; Zhang, Ling-Fan; Zhao, Yan-Hui; Yuan, Hui-Hui; Lan, Min-Bo; Lawrance, Geoffrey A.; Wei, Gang
- Relation
- Australian Journal of Chemistry Vol. 61, Issue 12, p. 962-967
- Publisher Link
- http://dx.doi.org/10.1071/ch08390
- Publisher
- CSIRO Publishing
- Resource Type
- journal article
- Date
- 2008
- Description
- A simple, disposable, and inexpensive electrochemical DNA biosensor based on a zirconia (ZrO₂) modified thin film screen-printed electrode (ZrO₂/SPE) has been developed. Short DNA sequences (21 monomer units) from the Escherichia coli pathogen, modified with a phosphate group at the 5′ end,were attached to the surface of the electrode through the affinity of the phosphate group for zirconia, to produce an effective DNA probe (ssDNA/ZrO₂/SPE). DNA immobilization and hybridization were characterized using differential pulse voltammetry by employing methylene blue as redox indicator. Target sequences hybridized with the probe resulted in a decrease of the reduction peak current of methylene blue intercalated into the probe. The response of a non-complementary sequence and a single base pair mismatch sequence were both clearly distinguished from that of a complementary sequence. The developed biosensor had a high selectivity and sensitivity towards hybridization detection (10⁻¹⁰M complementary DNA detectable). Making use of screen-printed technology, the fabrication of the biosensors exhibited satisfactory reproducibility, investigated by cyclic voltammetry and differential pulse voltammetry. The relative standard deviation was found to be <3.0% for six bare SPEs and six ssDNA-modified SPEs (ssDNA/ZrO₂/SPE) from a batch.
- Subject
- DNA; gold electrodes; methylene blue; thin films; hybridization; sensors; genes
- Identifier
- uon:5642
- Identifier
- http://hdl.handle.net/1959.13/43546
- Identifier
- ISSN:0004-9425
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