Page 108 - Organic Electronics in Sensors and Biotechnology

Or ganic Thin-Film Transistors for Inor ganic Substance Monitoring 85

The results confirm that Au-NP based FET sensors are able to
detect NO at concentration levels ranging from 50 to 200 ppm, with
x
high selectivity toward other species The increase of the operating
.
temperature from 150 to 175°C doubled the S/N ratio and improved
the sensitivity and recovery features, although a certain decrease in
the selectivity was observed as well.
We recently obtained some promising results on In O -NPs doped
2 3
with electrosynthesized Au-NPs as catalytic sensing layer in capaci-
tive FET sensors for NO monitoring. The Au-In O mixed system
206
x 2 3
was shown to exhibit enhanced sensing properties, at temperatures
as high as 400°C.
For low-temperature applications, active layers exclusively com-
posed of Au-NPs remain an interesting sensing material for NO
x
detection, and further research is in progress to improve their stability
at higher operating temperatures.
The possibility to work at temperatures higher than 200°C will
also enable faster response and recovery times, and this will allow the
sensor implementation in real systems, such as the manifold of cars,
for the online monitoring of NO .
x

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