All-solid-state composite copper(II)-selective potentiometric sensor

In this study, an all solid-state composite copper(II)-selective potentiometric sensor prepared by doping lead(II) sulfide (PbS) microparticles as ionophore into a mixture of graphite, multi-walled carbon nanotube, and paraffin oil was developed. The optimum composite composition of the developed sensor was determined as mass (w/w)10% PbS, 10% multi-walled carbon nanotube, 60% graphite, and 20% paraffin oil. The potentiometric performance characteristics of the developed electrode were determined in detail. The developed all solid-state composite copper(II)-selective potentiometric sensor exhibited a linear response (R2= 0.9992) to Cu(II) ions in the concentration range of 1.0×10-6-1.0×10-2 M Cu(II) ions with an average potential change of 30.2 mV/decade. The detection limit of the sensor was determined as 5.0×10-7 M. The potentiometric performance characteristics of the proposed sensor were found to be quite satisfactory, with fast response time (15 s), high sensitivity and selectivity, long lifetime, and high signal stability against Cu(II) ions. The developed all-solid-state composite copper(II)-selective potentiometric sensor was successfully used for the estimation of the equivalence points in titration applications and for the direct determination of Cu(II) ions in spiked water samples (tap waters with added Cu(II) ions).