dc.contributor.author |
Owino, Joseph H. |
|
dc.contributor.author |
Arotiba, Omotayo |
|
dc.contributor.author |
Songa, Everlyne |
|
dc.contributor.author |
Hendricks, Nicolette |
|
dc.contributor.author |
Waryo, Tesfaye |
|
dc.contributor.author |
Jahed, Nazeem |
|
dc.contributor.author |
Baker, Priscilla |
|
dc.contributor.author |
Iwuoha, Emmanuel |
|
dc.date.accessioned |
2015-07-30T08:37:06Z |
|
dc.date.available |
2015-07-30T08:37:06Z |
|
dc.date.issued |
2008 |
|
dc.identifier.citation |
Sensors 2008, 8(11), 6791-6809 |
en_US |
dc.identifier.issn |
1424-8220 |
|
dc.identifier.uri |
http://www.mdpi.com/1424-8220/8/11/6791/htm |
|
dc.identifier.uri |
http://repository.seku.ac.ke/handle/123456789/1353 |
|
dc.description |
doi:10.3390/s8116791 |
en_US |
dc.description.abstract |
An electrochemical DNA nanobiosensor was prepared by immobilization of a 20mer thiolated probe DNA on electro-deposited generation 4 (G4) poly(propyleneimine) dendrimer (PPI) doped with gold nanoparticles (AuNP) as platform, on a glassy carbon electrode (GCE). Field emission scanning electron microscopy results confirmed the co-deposition of PPI (which was linked to the carbon electrode surface by C-N covalent bonds) and AuNP ca 60 nm. Voltammetric interrogations showed that the platform (GCE/PPI-AuNP) was conducting and exhibited reversible electrochemistry (E°′ = 235 mV) in pH 7.2 phosphate buffer saline solution (PBS) due to the PPI component. The redox chemistry of PPI was pH dependent and involves a two electron, one proton process, as interpreted from a 28 mV/pH value obtained from pH studies. The charge transfer resistance (Rct) from the electrochemical impedance spectroscopy (EIS) profiles of GCE/PPI-AuNP monitored with ferro/ferricyanide (Fe(CN)63-/4-) redox probe, decreased by 81% compared to bare GCE. The conductivity (in PBS) and reduced Rct (in Fe(CN)63-/4-) values confirmed PPI-AuNP as a suitable electron transfer mediator platform for voltammetric and impedimetric DNA biosensor. The DNA probe was effectively wired onto the GCE/PPI-AuNP via Au-S linkage and electrostatic interactions. The nanobiosensor responses to target DNA which gave a dynamic linear range of 0.01 - 5 nM in PBS was based on the changes in Rct values using Fe(CN)63-/4- redox probe. |
en_US |
dc.language.iso |
en |
en_US |
dc.publisher |
MDPI |
en_US |
dc.subject |
Poly(propyleneimine) dendrimer |
en_US |
dc.subject |
gold nanoparticle |
en_US |
dc.subject |
lectrochemical impedance spectroscopy |
en_US |
dc.subject |
electrochemical DNA biosensor |
en_US |
dc.subject |
DNA |
en_US |
dc.title |
An Electrochemical DNA Biosensor Developed on a Nanocomposite Platform of Gold and Poly(propyleneimine) Dendrimer |
en_US |
dc.type |
Article |
en_US |