Biology Reference
In-Depth Information
Consequently,mismatchdetectionwasaccomplishedbyvoltammet-
ric transduction ofMB accumulation.
The application of clinical analyses from real samples was
determined with HBV detection. For this purpose; we developed
a genosensor for clinical analysis of HBV based on MB indicator
[66]. In this study, real samples were used first time for medicinal
analyses. 24-mer capture probe related to HBV genome were
immobilized onto CPE electrostatically, the hybridiziation with
PCR amplicon and accumulation of MB was applied. Hybridization
detection was accomplished by monitoring the DPV reduction
signalsof MB.
13.3.1.2 Electrochemical genosensing with labeled signaling
probe or labeled target DNA
Another approach to electrochemical biosensing of microbiological
and inherited diseases is to use labels attached onto capture probe
ortargetsequences.Ifaredoxactivemoleculesuchasferrocenehas
been attached to probe sequence, the electron transfer of double-
stranded DNA has been insensitive due to the distance from the
electrodesurface[67].Ferrocene(Fc)anditsderivatesareattractive
redox active chemicals because of their stability [68]. Yu
et al.
[69]
prepared ferrocene-labeled oligonucleotides that were conjugated
with uridine. With the same technique, Yu [70] performed an
SNP detection based on DNA/RNA hybrids. Xu
et al.
[71] used
ferrocenecarboxaldehyde (FCA)-modified ssDNA probes bounded
atchitosan-modifiedelectrodesurfaces.Chitosan-modifiedgraphite
surfaces provided a strong binding of probe sequence at the
surface, and hybridization detection was accomplished with DPV
transduction of FCA. 5'-FC-modified hairpin DNA probe was used
for sequence specific detection. Genosensing was performed by
transduction of AC voltammetry and differences in melting points
between FC-modified hybrid andunmodified target sequences[72].
The biotin-avidin system is used in a variety of biotech-
nological and diagnostic applications. It involves a chemical or
genetic (the bio-tag biotinylation) biotinylation step. Mascini used
biotinylated oligonucleotides for electrochemical genosensing [73].
Thiol-tethered capture probe was immobilized onto Au-SPE and
