Biology Reference
In-Depth Information
based on gold nanoparticles [31]. The method differed slightly
from Ligomes's work in that instead of microwells, magnetic beads
were used, and electrochemical detection was by potentiometric
stripping analysis. The protocol was based on the hybridization of
a target oligonucleotide to a magnetic bead-linked probe, followed
bybindingofstreptavidin-coatedgoldnanoparticlestothecaptured
DNA,thendissolutionofthegoldlabelandpotentiometricstripping
measurement of the liberated Au
3
+
ions at a screen-printed carbon
electrode, as depicted in Fig. 8.3. Alternatively, direct oxidation,
using DPV, of the gold nanoparticle label contained in a duplex
Figure 8.3.
DNA detection scheme based on immobilizing DNA probes
ontomagneticbeadsandattachingindividualgoldnanoparticlestotheDNA
targets after hybridization. Following dissolution Au
3
+
ions are quantified
by PSA. Taken with permission from [31], J. Wang, D. Xu, A.-N. Kawde, and
R.Polsky,
Anal. Chem
.
73
,5576-5581(2001). c
AmericanChemicalSociety.
