Biomedical Engineering Reference
In-Depth Information
(r)
fabrication of screen-printed carbon electrodes (SPCEs) by a novel one-step process for
manufacturing electrodes for injection molding (
Wu et al., 2008
), and
(s)
a rapid and easy procedure for fabrication of biosensors by microencapsulation of an
enzyme in hydrophilic synthetic latex films.
3.2 Different Methods of Biosensor Fabrication
We now examine some of the biosensor fabrication techniques that have appeared recently in
the open literature. These include a novel nanocomposite electrode (
Safavi et al., 2009
),
microbial biosensors using screen-printing water-based carbon ink (
Pemberton et al.,
2009
), using surface molecular imprinting (
Wang et al., 2008; Henry et al., 2008
), using pro-
cessable conducting polyaniline nanoparticles (
Morrin et al., 2005a,b
), using screen printing
(
Schuler et al., 2009; Kadara et al., 2009
), using ink-jet printing (
Carter et al., 2006
), and
using charge transfer techniques (
Lee et al., 2009
).
3.2.1 Fabrication of a Glucose Sensor Based on a Nanocomposite Electrode
(
Safavi et al., 2009)
Safavi et al. (2009)
have very recently presented a novel technique for the fabrication of a
glucose sensor based on a novel nanocomposite electrode. These authors point out that there
has been considerable emphasis on the development of glucose sensors which involves the
immobilization of glucose substrates (
Lin et al., 2004; Maleki et al., 2007; Zhang et al.,
2007; Musameh et al., 2008; Jeykumari and Narayanan, 2008; Deng et al., 2008
).
As early as 1972,
Wilson and Turner (1992)
indicated that the loss of enzyme stability or
insufficient stability as one of the major problems during the immobilization process which
leads to a loss of sensitivity and affects reproducibility. Further problems arise due to the
interference caused by endogeneous electroactive ascorbic acid (AA) and uric acid (UA) in
blood samples.
Safavi et al. (2009)
emphasize that electrocatalytic activity is the key factor
that affects sensitivity and selectivity during glucose detection.
Safavi et al. (2009)
point out that nanomaterials have been introduced in electrochemical
sensing. They exhibit increasing surface area, mass transfer, and catalysis (
Katz et al.,
2006
). Some of the more recent applications for nanomaterials in biosensing include a Pt
nanotubular array (
Yuan et al., 2005
), mesoporous Pt (
Park et al., 2003
), Ni nanoparticles
(
You et al., 2003
)
, Au nanoparticles (
Jena and Raj, 2006; Kurniawan et al., 2004
), Pt
nanoparticles (
Rong et al., 2007
), Pt/Pb nanoparticles (
Cui et al., 2007
;
Wang et al., 2008
),
and CNTs (
Ye et al., 2004; Tan et al., 2008
).
Safavi et al. (2009)
report on the fabrication of a novel nonenzymatic composite electrode
based on powdered nanoscale nickel hydroxide, graphite powder, and ionic liquid
(octylpyridium hexafluorophosphate, OPy
4
PG
6-
). They indicate that their nanosensor is stable
