Biomedical Engineering Reference
In-Depth Information
Morrin et al. (2005a,b)
claim that electrodeposition is not a technique that leads to effective
mass production of biosensors. They report that drop-coating is a simpler method of electrode
modification. This, they indicate, combined with screen-printed electrodes could then be
amenable to mass production. They further state that the enzyme could either be drop-coated
in a simultaneous or sequential manner. This should lead to a simple method for biosensor
fabrication.
Finally,
Morrin et al. (2005a,b)
report that the casting of conducting polyaniline nanoparticles
and enzymes simultaneously by drop-coating on screen printed electrodes is an effective
method of biosensor fabrication. The enzyme, horse-radish peroxidase (HRP) was
incorporated before casting. The HRP was incorporated into the films so that a working biosen-
sor could be constructed to detect the substrate H
2
O
2
. Different methods for immobilizing the
HRP were examined. The pH of the nanoPani/DBSA (dodecylbenzenesulphonic acid) disper-
sion is adjusted to 7.0 prior to the addition of HRP. The authors report that the thickness of the
polymer film deposited does limit its potential. A better technique is required for a thinner and
more homogeneous film deposition.
Morrin et al. (2005a,b)
are examining ink-jet printing as
an alternate casting method. The goal is to provide a single-step mass production method of
fabricating enzyme biosensors. Perhaps, according to these authors, manipulation of the ink-
jet printing technique may lead to a more sophisticated biosensor fabrication technique.
3.2.7 Screen-Printing for DNA Chips with an Electrical Readout for the Detection
of Viral DNA (
Schuler et al., 2009
)
Schuler et al. (2009
) have recently reported that screen printing is a cost-efficient fabrication
technique for DNA chips with an electrical readout for the detection of viral DNA. These
authors point out that the identification and analysis of biomolecules is important in the fields
of life sciences, food technology, and in forensic and environmental research (
Schena et al.,
1998
). Microarray technology provides for high throughput as well as high sensitivity (
Wang,
2000; Schena, 2003
). Biochips are used (as microarray-based approaches) to detect binding
events (
Choi et al., 2007; Marquette et al., 2008
).
Schuler et al. (2009)
report that simple
detection methods that require only simple instrumentation techniques are gaining popularity
(
Cheung et al., 1999; Heller, 2002
).
Schuller et al. (2009)
indicate that screen printing technology is one of the oldest forms of
graphic art reproduction and its characteristic, as different from other forms of
microstructuring, is its film deposition. It has been widely used for the large-scale fabrication
of disposable biosensors. This is due to its low cost, versatility, and miniaturization.
Tudorache and Bala (2007)
report that modern sensors may be integrated into portable forms,
thereby permitting analytical methods for on-site testing. Personal glucose biosensors used by
diabetic patients is a good example of the use of screen printing technique for fabricating
biosensors (
Matthews et al., 1987; Nagata et al., 1995
).
