Biology Reference
In-Depth Information
allows repeated analyses with the same electrode as the Av-GEB
platform can be considered not only the transducer but also the
reservoir forthe avidin.
The same immobilization strategy based on avidin/biotin link-
age can be achieved on magnetic beads. After their e
cient mod-
ification, the magnetic beads can be easily captured on an m-GEC
transducer for the electrochemical determination of the hybridiza-
tion event.
The sensibility conferred by the m-GEC electrode in connection
with the use of magnetic beads and enzymatic labeling results in a
rapid, cheap, robust, and environment-friendly device which allows
thedetectionofpathogenicspeciesonfood,environmental,andclin-
ical samples.
The single-point attachment of DNA can also be achieved by
chemisorption of thiolated DNA on nanoAu-GEC platform. The
capability of surface regeneration of the nanocomposite electrodes
allows repeated analyses with thesame electrode.
GEC materials present a low non-specific adsorption either for
DNAprobesorenzymelabels.Theydonotrequireblockingstepsto
minimize the non-specific adsorption on the free sites of the trans-
ducer.
Although the non-specific adsorption issues are controlled on
GEC, stringent conditions can be achieved when using avidin/biotin
linkage than when DNA is simply adsorbed, allowing rigorous con-
ditionsfor hybridizationover longertimes.
DNA biosensors based on GEC meet the demands of genetic
analysis, especially in food, biotechnology, and pharmaceutical
industries, while also generating new possibilities for the develop-
mentofDNAbiosensorsthataresensitive,robust,lowcost,andeas-
ily produced.
Foralltheaforementionedreasons,itispossibletoconcludethat
GEC-basedmaterials are very suitableplatforms forDNA analysis.
References
1. D. Baltimore, Ourgenome unveiled,
Nature
,
409
,814-816 (2001).
2. D. D. L. Bowtell, Options available—from start to finish—for obtaining
expression data by microarray
, Nature Gen. Suppl
.,
21
,25-32 (1999).
