A new ion selective electrode for cesium (I) based on calix[4]arene-crown-6 compounds

► First report on Cs(I)-ISE employing 25,27-bis(1-octyloxy)calix[4]arene-crown-6. ► Higher sensitivity and selectivity achieved by minimizing trans-membrane fluxes. ► 10 months life time is longest reported so far for membrane based Cs-ISE. ► Cesium is chemically toxic displaces potassium from muscles and red blood cells. ► Its monitoring in environment is essential.