Biology Reference
In-Depth Information
whereas the low intrinsic electrocatalytic activity of ITO electrodes
minimized the background current. With this method, 1fM of target
DNA in an electrochemical DNA sensor was detected without the
need of target or enzymaticsignalamplification [29].
5.2.3
Electrocatalytic Activity of Gold Nanoparticles Used
as Modifiers of Electrotransducer Surfaces
Another application of metal nanoparticles in electrochemical
detection of DNA is their incorporation with composites used as
electrode surface modifiers. Even though these modified electrodes
canshowhigherbackgroundsignalsthantheunmodifiedelectrodes,
the incorporation of Au-NPs can be used to promote selective
immobilizationspots to well-orientedDNA detection probes.
Liu
et al.
[9]haverecentlyreportedtheapplicationofcomposites
of Au-NPs and multi-walled carbon nanotubes (Au-NPs/MWCNT)
for enhancing the electrochemical detection of DNA hybridization.
Au-NPs were deposited onto the surface of MWCNTs by one-step
reaction and then a thiolated-DNA probe was immobilized onto the
Au-NPs/MWCNTs-modified glassy carbon electrode (GCE) through
the strong gold-sulfur linkage, which could control the molecular
orientation of probe DNA. On the basis of DNA detection it was
foundthattheAu-NP/MWCNTcompositescouldhighlyimprovethe
sensitivityofDNAbiosensorduetotheirenhancedconductivityand
increased effective surface area. Furthermore, it was revealed that
selectivityandreproducibilityoftheDNAsensorwerealsoexcellent,
which resulted in a significant platform for the hybridization
detection of DNA.
5.3 Catalysis Induced by Platinum and
Palladium Nanoparticles
5.3.1
Electrocatalytic Activity of Platinum Nanoparticle
Labels
Despite the high cost of this metal in the bulk state, the subsequent
saving that reducing the metal size implies placed platinum
nanoparticles (Pt-NPs) in the centre of attention of scientists due to
theirabilitytobeusedascatalystformanyindustrialprocesses[13].
