Next Article in Journal
Next Article in Special Issue
Previous Article in Journal
Sensors 2008, 8(11), 6791-6809; doi:10.3390/s8116791
Article

An Electrochemical DNA Biosensor Developed on a Nanocomposite Platform of Gold and Poly(propyleneimine) Dendrimer

,
,
,
,
,
,
 and *
Received: 29 September 2008; in revised form: 22 October 2008 / Accepted: 27 October 2008 / Published: 1 November 2008
(This article belongs to the Special Issue Dendritic Sensors: From Dendrimer Molecules to Dendritic Cells)
View Full-Text   |   Download PDF [846 KB, uploaded 21 June 2014]
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)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.
Keywords: Poly(propyleneimine) dendrimer; gold nanoparticle; electrochemical impedance spectroscopy; electrochemical DNA biosensor; DNA Poly(propyleneimine) dendrimer; gold nanoparticle; electrochemical impedance spectroscopy; electrochemical DNA biosensor; DNA
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Export to BibTeX |
EndNote


MDPI and ACS Style

Arotiba, O.; Owino, J.; Songa, E.; Hendricks, N.; Waryo, T.; Jahed, N.; Baker, P.; Iwuoha, E. An Electrochemical DNA Biosensor Developed on a Nanocomposite Platform of Gold and Poly(propyleneimine) Dendrimer. Sensors 2008, 8, 6791-6809.

AMA Style

Arotiba O, Owino J, Songa E, Hendricks N, Waryo T, Jahed N, Baker P, Iwuoha E. An Electrochemical DNA Biosensor Developed on a Nanocomposite Platform of Gold and Poly(propyleneimine) Dendrimer. Sensors. 2008; 8(11):6791-6809.

Chicago/Turabian Style

Arotiba, Omotayo; Owino, Joseph; Songa, Everlyne; Hendricks, Nicolette; Waryo, Tesfaye; Jahed, Nazeem; Baker, Priscilla; Iwuoha, Emmanuel. 2008. "An Electrochemical DNA Biosensor Developed on a Nanocomposite Platform of Gold and Poly(propyleneimine) Dendrimer." Sensors 8, no. 11: 6791-6809.


Sensors EISSN 1424-8220 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert