Biology Reference
In-Depth Information
Figure 12.4.
Electrochemical detection of substance-DNA interactions
based on sensor surface.
The decrease or increase of the intrinsic guanine oxidation
signal enables the monitoring of the DNA-molecule interactions
electrochemically; these events especially give an idea about the
DNA damage. Additionally, if it is obtained as a new peak in the
voltammogram, then this situation reflects the extent of an adduct
formation [52]. All this qualitative work related to measurements
of the difference in the peak heights of the electrochemical signals
were examined with dsDNA- or ssDNA-modified sensor before and
after the interaction with acompound.
In order to prove that one compound specifically interacts with
guanine and adenine bases, some experiments can be performed
by using synthetic polynucleotides of guanine (poly[G] and adenine
(poly[A]) [53].
In compound-DNA interaction studies, three different assump-
tions could be put forward to explain the decrease in the guanine
oxidation signal: (a) the decrease in the peak height of guanine
could be explained by the covering of oxidizable groups of guanine
while a molecule interacts with DNA, (b) the binding of a chemical
compoundtoguaninebases,andthus,formingadamageinguanine,
reviewed in Refs. 28 and 54-56, and (c) after the interaction with
thecompound,achangeinthecharge-transferpropertiesofDNA
[57, 58] could decrease the signal observed from the oxidation of
guanineat CGE surface.
