Development of a Chloride Ion-Selective Solid State Sensor Based on Doped Polypyrrole-Graphite-Epoxy Composite

This paper reports the development and characterization of a solid state potentiometric sensor for chloride ions, based on doped polypyrrole-graphite-epoxy composite. The optimum mixture proportion found for polypyrrole:graphite was 60?:?40 meanwhile a 50?:?50 proportion was used for the polypyrrol+graphite:epoxy mixture. The stabilization time was approximately 16?min, while the response times varied within 2 and 23?s. The sensor displayed a sensitivity of 58?mV/decade [Cl?], and 3×10?6?M detection limit. The selectivity coefficients showed a greater selectivity to that reported for commercial-type sensors. The statistical analysis for chlorides' determination in commercial saline serums did not show significant differences respect to data reported by the manufacturers.