Biomedical Engineering Reference
In-Depth Information
important substances. All these advantageous features can make the pro-
posed biosensor applicable in wireless physiological parameters monitor-
ing, environmental, food or other areas.
Recently, Ali
et al.
[29] designed a prototype wireless remote glucose
monitoring system interfaced with a ZnONW arrays-based glucose sen-
sor. h e GOx was immobilized onto ZnONWs in conjunction with a
Nai on membrane coating, using an existing general packet radio services
(GPRS)/global system for mobile communication (GSM) network. h ey
demonstrated the remote monitoring of patients' glucose levels with exist-
ing GPRS/GSM network infrastructures using their proposed function-
alized ZnONW arrays sensors integrated with standard readily available
mobile phones. h e proposed potentiometric ZnO nanosensor device
showed good linearity and negligible interference of anionic species like
uric and ascorbic acids. h e calibration curve for glucose is linear from
0.5 μM to 10 mM, with an LOD of 0.5 μM. h is proposed system can pro-
vide a means of using emerging nanosensors/nanodevices for monitoring
multiple health parameters outside the traditional hospital environment
and ei ciently transferring data to physicians for immediate consultation
in case of urgent need. Such an application can reduce health care costs and
allow caregivers to monitor and support their patients remotely, especially
those located in rural areas. In the future, similar techniques with various
ZnO nanostructure-based platforms can provide nanosensor/nanodevices
for monitoring multiple health parameters outside central labs.
Ya n o
et al.
[30] studied the characteristics of two dif erent types of zinc
oxide (ZnO)-based glucose biosensors using Gox, keeping medical appli-
cations in mind: one is a Gox-immobilized amperometric electrode based
on ZnONRs with an expectation of high sensitivity, and the other is a GOx-
immobilized FET based on a polycrystalline ZnO i lm for potentiometric
detection foreseeing its integration on health care chips.
A potentiometric and ei cient tunable glucose biosensor was fabricated
using a core-shell nanocomposite based on ZnO encapsulated chitosan-
grat
-poly(vinyl alcohol) (ZnO/CHIT-
g
-PVAL) [31]. h e glucose respon-
sive bioelectrode, i.e., GOx/ZnO/chitosan-
grat
-poly(vinyl alcohol) (GOx/
ZnO/CHIT-
g
-PVAL/ITO) was obtained by immobilization of GOx onto
the electrode made of resulting ZnO core-shell nanocomposite coated on
the ITO glass substrate (Figure 1.7). h e electrostatic interaction between
GOx and ZnO/CHIT-
g
-PVAL provided the resulting tuned enzyme elec-
trode with a high degree of enzyme immobilization and excellent lifetime
stability. h e GOx/ZnO/CHIT-
g
-PVAL/ITO showed a linear potential
response to the glucose concentration ranging from 2 μM to 1.2 mM, a fast
surface-controlled redox biochemistry with a LOD of 0.2 μM, a sensitivity
