DNA impedance biosensor for detection of cancer, TP53 gene mutation, based on gold nanoparticles/aligned carbon nanotubes modified electrode.

Abstract

For the first time, a new platform based on electrochemical growth of Au nanoparticles on aligned multi-walled carbon nanotubes (A-MWCNT) was developed for sensitive lable-free DNA detection of the TP53 gene mutation, one of the most popular genes in cancer research. Electrochemical impedance spectroscopy (EIS) was used to monitor the sequence-specific DNA hybridization events related to TP53 gene. Compared to the bare Ta or MWCNT/Ta electrodes, the synergistic interactions of vertically aligned MWCNT array and gold nanoparticles at modified electrode could improve the density of the probe DNA attachment and resulting the sensitivity of the DNA sensor greatly. Using EIS, over the extended DNA concentration range, the change of charge transfer resistance was found to have a linear relationship in respect to the logarithm of the complementary oligonucleotides sequence concentrations in the wide range of 1.0×10(-15)-1.0×10(-7)M, with a detection limit of 1.0×10(-17)M (S/N=3). The prepared sensor also showed good stability (14 days), reproducibility (RSD=2.1%) and could be conveniently regenerated via dehybridization in hot water. The significant improvement in sensitivity illustrates that combining gold nanoparticles with the on-site fabricated aligned MWCNT array represents a promising platform for achieving sensitive biosensor for fast mutation screening related to most human cancer types.

• Authors: H Fayazfar, A Afshar, M Dolati, A Dolati
• Journal: Analytica chimica acta (Anal Chim Acta) Vol. 836 Pg. 34-44 (Jul 11 2014) ISSN: 1873-4324 [Electronic] Netherlands
• PMID: 24974868 (Publication Type: Journal Article)
• Copyright: Copyright © 2014. Published by Elsevier B.V.

Chemical References

• DNA Probes
• Nanotubes, Carbon
• Gold

Topics

• Biosensing Techniques (instrumentation, methods)
• DNA Mutational Analysis (methods)
• DNA Probes (genetics)
• Dielectric Spectroscopy
• Electrochemical Techniques
• Electrodes
• Genes, p53
• Gold
• Humans
• Limit of Detection
• Nanotubes, Carbon
• Neoplasms (genetics)
• Nucleic Acid Hybridization
• Reproducibility of Results