Biomedical Engineering Reference
In-Depth Information
Ashburn and Sun (2009)
emphasize that amorphous silicon cannot be used because its mobil-
ity is low. They explored the possibility of using nickel-induced lateral crystallization to con-
vert this amorphous silicon to polycrystalline silicon using a low temperature anneal. This,
they felt, should lead to a better biosensor performance for their biosensor since polycrystal-
line silicon has better mobility than amorphous silicon. These authors looked at Si-on-oxide
and Si-on-air. They noted that Si-on-oxide was easier to fabricate though the Si-on-air con-
figurations permitted biomolecule attachment all around the nanowire. This, they report,
should lead to a higher sensitivity. These authors are currently exploring other avenues such
as fluorine implantation to enhance the crystallization process.
3.2.14 Clinical Evaluation of Bionime Rightest GM310 with a Simplified Electrode for
Alternate Site Blood Glucose Tests (
Wu et al., 2008
)
Wu et al. (2008)
have reported that most processes for fabricating biosensors by the SPCEs
process are complex. These authors have recently developed a novel one-step process for
manufacturing electrodes for injection molding. They inserted barrel-plated gold electrodes
into an injection-molded base. Their electrode was in direct electrical contact with a meter.
They measured glucose levels at the finger tip, palm, and arm, and compared the results with
plasma values obtained by the hexokinase method on an Olympus AU640 instrument. They
obtained good reproducible results. When their Rightest GM310 meter results were compared
with those obtained by a laboratory method, their results complied with the ISO 15197:2003
criteria. These authors conclude that their Bionime Rightest GM310 meter used a simplified
biosensor fabrication process, and exhibited reasonable performance for monitoring glucose
at alternative test sites.
3.2.15 Biosensor Fabrication Method Using Microencapsulation of Enzyme in
Hydrophobic Synthetic Latex Films: Amperometric Determination of Glucose
(
Cosnier et al., 2000a,b
)
Cosnier et al. (2000a,b)
have developed novel enzyme electrodes based on synthetic hydro-
phobic latex matrices which may be used for glucose detection. These authors used microen-
capsulation to immobilize glucose oxidase by using simple adsorption of enzyme-latex
suspensions on the surface of a platinum electrode. They used two latex films functionalized
by a hydroxyl or a glucoamide group. Their biosensors were able to provide a quantitative
estimate of the glucose present by potentiostating the modified electrode at 0.6 V/SCE. This
was done to oxidize the hydrogen peroxide generated by the enzymatic oxidation of glucose
in the presence of dioxygen. The authors evaluated the response of their electrodes as a func-
tion of temperature and film thickness. They noted that their biosensor was stable; however,
it is only at temperatures above 65
C that the glucose oxidase started to denature and
became inactive.
