Biology Reference
In-Depth Information
Adenosine, cytosine, guanosine, and thymidine mononucleotides
were linked to ZnS, CdS, PbS, and CuSnanoparticles, respectively,
and sequentially introduced to a DNA hybrid-coated magnetic
bead solution. Characteristic multipotential voltammetric peaks
were produced depending on the base pairing of the different
nanocrystal-mononucleotide conjugates with each mutation capa-
ble of identifying each of eight possible one-base mutations in a
singlerun.
Ying has described two solid-state approaches based on the
incorporation of silver nanoparticles into DNA duplexes followed
by the direct detection of the nanoparticles based on an Ag/AgCl
cycling process shown in Fig. 14.5. In the first approach neutral
PNA, which can significantly increase DNA hybridization e
ciency
due to a lack of electrostatic repulsion of the DNA target, was
used as the probe capture molecule [32]. Following target DNA
hybridization the surface would become negatively charged and
couldthenbelabeledwithpositivelychargeddodecylamine-capped
Ag nanoparticles (Fig. 14.5A). In the second approach a normal
thiolatedDNAmixedmonorecognitionlayerwasusedinconnection
Figure 14.5.
Schematic for biosensing strategy using (A) dodecylamine-
capped Ag nanoparticles and (B)doxorubicin-modified Ag nanoparticles.
