Biology Reference
In-Depth Information
chemistry. The extremely promising prospects of nanomaterials-
based biodevices accrue from the unique properties of nanomateri-
als,makingpossibleadvancedapplicationswherelimitsofdetection
atzeptomolarconcentrationsandultra-sensitivemultiplexeddetec-
tion can be achieved [1]. Different types of nanomaterials can be
employed to design and construct these biosensing devices: carbon
nanotubes, nanowires including metal, silicon, conducting polymer,
and metal oxide nanowires, nanocantilivers, quantum dots, and
nanoparticles, including metal, metal oxide, semiconductor, and
magneticnanoparticles.Aniceoverviewontheuseofnanomaterials
for the construction of biosensors can be found in the monography
edited by Kumar [1].
In this context, the preparation of nanostructured electrode
surfaces constitutes also a priority research line with high activity
in the field of electroanalytical chemistry [2]. This electrode
modification strategy combines, on the one hand, advances in
sensor technology, offering a wide range of approaches using or
not biological systems, as well as several (bio)assay-transduction
symbiotic strategies, and, on the other hand, the applications of
nanotechnology in its wider sense as the products, processes, and
systems operating at nanometric scale. The use of nanostructured
electrodesurfacesproducessignificantadvantagesfromtheelectro-
analytical point of view. In general, they improve the kinetics of the
electron-transfer reactions, exhibit electrocatalytic ability toward
many electrochemical processes of biological significance allowing
the detection potentials to be lowered, and show an anti-fouling
capabilityfortheproductsofmanyelectrochemicalreactions.These
characteristics improve basic analytical properties such as the
sensitivityandselectivityofthemethodsandtherepeatabilityofthe
measurements.
Although most of the nanomaterials mentioned above can be
employed for this purpose, gold nanoparticles play a key role in the
construction of a new generation of biosensors and, in particular,
of electrochemical biosensors. The ability of gold nanoparticles to
provide a stable surface for the immobilization of biomolecules
retaining their biological activity is a major advantage for the
preparation of biosensors. Moreover, gold nanoparticles allow
direct electron transfer between redox proteins and bulk electrode
