The integration of chemo/bio sensors in large wireless sensing networks (WSN) is currently
limited, largely due to the issues related with power consumption and data handling.
Also, there are very few low cost chemo/bio sensors that combine sensitive, low limit
of detection capabilities with simple experimental setup. However, with recent advances,
ion-selective electrodes (ISEs) may become an excellent candidate for deployment in
WSNs.In this paper, we describe a solid-contact electrode based on poly(3-octylthiophene)
(POT) as an internal contact. We report its characteristics and its application to
the for measurement of Pb2+ in 16 soil samples, with a ultimate goal of producing
a small, simple and sensitive sensor that can be integrated into WSNs. The electrode
had a detection in the soil digestion matrix (1 x 10(-3) M HNO3) Of 1 x 10(-7) M (20
ppb). The electrodes results were compared with atomic absorbtion spectrometry (AAS)
as a common instrumental technique used in soil analysis. We also report on the performance
of solid-contact ISEs based on polypyrrole (PPy) and POT. A superior detection limit
of POT-relative to PPy-based ISEs was observed. Furthermore, a good correlation has
been observed between POT-based ISEs and AAS and between the two types of ISEs.
