Carbon nanotubes versus polyaniline nanoparticles; which transducer offers more opportunities for designing a stable solid contact ion-selective electrode

Abstract

Sensors that exploit the unique properties of nanomaterials establish the most rapidly growing sensor research area. Remarkable achievements in nanotechnology and ion selective electrodes (ISEs) lead to explore a wide variety of approaches that develop completely calibration-free ISEs. This work offers construction and comparative evaluation of the performance characteristics of multiwall-carbon nanotubes (CNTs) and polyaniline nanoparticles (PANI) as ion-to-electron transducers between an ionophore-doped PVC membrane and glassy carbon electrodes. With respect to the previously published reports, the current comparison was performed side by side under similar experimental conditions and hence the advantages and shortcomings of each transducer nanoparticles were directly highlighted in light of ISE figures of merit. Apparently, the inclusion of CNTs and PANI nanoparticles added more stability to the electrical signal due to their excellent electronic and chemical properties. Moreover, the fast ion-to-electron transduction allows obtaining short response times and the hydrophobic behavior avoids the formation of water layers at the electrode/membrane interface. These results enabled the production of a series of SC-ISEs with improved piece-to-piece reproducibility where the potential was stable over 60 and 45days with drift of 0.8mVh−1 and 0.7mVh−1 for CNT and PANI based sensors, respectively. The electrodes were utilized for determination of buspirone as a model pharmaceutical drug.