(IEEE, 2009-01-22) Hernáez Sáenz de Zaitigui, Miguel; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ruiz Zamarreño, Carlos; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, a novel application of the electric field
directed layer-by-layer self assembly (EFDLA) selective
deposition method for the fabrication of optical fiber pH sensors
is presented. Here, indium tin oxide (ITO) coated optical fibers
have been fabricated via a dip-coating deposition method. These
fibers are used as electrodes in the EFDLA protocol in order to
deposit selectively the sensitive layer. Neutral Red (NR)
colorimetric pH sensitive indicator and the polymers
poly(acrylic acid) (PAA) and poly(allylamine hydrochloride)
(PAH) are used in order to obtain a pH sensitive nanostructured
coating onto ITO coated optical fibers. The results obtained in
this work revealed that the LbL material adsorption on the
electrodes can be enhanced or even inhibited when applying a
specific direct current voltage between them under some other
specific fabrication parameters. Particularly, the response of
these sensors to variations of the pH in the surrounding medium
was studied when the pH of the solutions used for the
fabrication of the films was adjusted to 7.0 and the potential
applied between electrodes was set to 2.5 V. These sensors
showed fast response time and high repeatability.
