Robust single-piece all-solid-state potassium-selective electrode with monolayer-protected Au clusters

High stability of the signal and simplicity in fabrication of the device are the two important requirements in development of potentiometric sensors, A robust single-piece all-solid-state potassium-selective electrode (K-SPE) was developed by incorporating monolayer-protected Au clusters (MPCs) as advanced ion-to-electron transducers into a conventional ion-selective membrane (ISM). The extraordinary properties of MPCs such as high solubility, profound hydrophobicity and large capacitance make them quite suitable to be used in fabrication of single-piece electrodes (SPEs) with advanced performance. The developed KSPEs containing small amount of MPCs in the membrane showed a significant increase in the potential stability (12.9 mu V/h), lower detection limit (10(-6.1) M) and prolonged life time (high performance still after 3 weeks). The multi-valence MPCs in the membrane facilitated the ion-to-electron transduction and fast establishment of the potential equilibrium resulting in-fast response time in potential measurements. The inserted MPCs did not cause any interference either in the potential formation process or in the selectivity of the ion-selective membrane. (C) 2016 Elsevier B.V. All rights reserved.