Biology Reference
In-Depth Information
14.3.1
Nanorods as Labels
Use of nanorods as labels for electrochemical detection of DNA was
first reported by Wang and coworkers [41]. In this work conical
indium/gold nanorods, approximately 3 to 5
μ
minlength,were
synthesized via sequential electrodeposition of Au and indium into
alumina membranes. Following synthesis, the alumina template
was dissolved in 3 M NaOH yielding free nanorods (Fig. 14.8B).
These rods were then modified with thiolated oligonucleotide
detectionprobes,complementarytoaportionofthetargetDNA,via
Figure 14.8.
(A) Schematic representation showing sandwich hybridiza-
tion linking magnetic beads and indium/gold nanorods through the DNA
target, magnetic collection of the DNA-linked particle assembly onto the
thick-film electrode transducer, and solid-state derivative chronopotentio-
metricmeasurementsofthecapturedindiumrods.P
1
,DNAprobe1;T,DNA
target; P
2
, DNA probe 2; MR, indium/gold nanorods; MB, magnetic beads;
and M, external magnet. SEM images of (B) indium/gold rods and (C) DNA-
linked particle assembly (aftersandwich hybridization assay).
