dc.contributor.author | Arotiba, Omotayo A. | |
dc.contributor.author | Owino, Joseph | |
dc.contributor.author | Songa, Everlyne | |
dc.contributor.author | Hendricks, Nicolette | |
dc.contributor.author | Waryo, Tesfaye T. | |
dc.contributor.author | Jahed, Nazeem | |
dc.contributor.author | Baker, Priscilla | |
dc.contributor.author | Iwuoha, Emmanuel I. | |
dc.date.accessioned | 2016-12-21T12:25:01Z | |
dc.date.available | 2016-12-21T12:25:01Z | |
dc.date.issued | 2008 | |
dc.identifier.citation | Omotayo, A. et al. (2008). An electrochemical DNA biosensor developed on a nanocomposite platform of gold and poly(propyleneimine) dendrimer. Sensors, 8: 6791-6809 | en_US |
dc.identifier.issn | 1424-8220 | |
dc.identifier.uri | http://hdl.handle.net/10566/2474 | |
dc.identifier.uri | http://dx.doi.org/10.3390/s8128262 | |
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 codeposition
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)6
3-/4-) redox probe, decreased by 81% compared to bare GCE. The conductivity (in
PBS) and reduced Rct (in Fe(CN)6
3-/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)6
3-/4- redox probe. | en_US |
dc.language.iso | en | en_US |
dc.publisher | MDPI | en_US |
dc.rights | All articles published by MDPI are made immediately available worldwide under an open access license. | |
dc.subject | Poly(propyleneimine) dendrimer | en_US |
dc.subject | Gold nanoparticle | en_US |
dc.subject | Electrochemical 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 |