In this work, a highly conductive treated PEDOT:PSS (poly(3,4-ethylenedioxythiophene)
: poly(styrene sulfonate)) layer was utilized for the transduction layer of an ion-selective
flexible electrode (ISFE) and well-deposited on the carbon paste and polyethylene
terephthalate (PET) substrate. The PEDOT:PSS was also treated by a co-solvent of ethylene
glycol (EG) using bath-sonication to enhance electrical and electrochemical characteristics
and finally coated with Ca2+ selective membrane cocktail. Electrochemical properties
exhibited that EG treated PEDOT:PSS drop-casted ISFE achieves improved charge transport
with remarkable electric conductivity enhancement. The fabricated Ca2+-ISFE was demonstrated
a near-Nernst response of 31.9 mV/decade between 10(-4) and 10(-1) M with the rapid
response (< 20 seconds). Moreover, the EG-treated PEDOT:PSS based ISFE proved significant
potential stability with a negligible potential drift of 0.34 mV/min, compared to
pristine PEDOT:PSS based ISFE (0.56 mV/min). Based on these analyses, it can be expected
that the EG-treated PEDOT:PSS will pave the way for other bio-chemical compounds monitoring.
