Development of an electrochemical sensor for potassium ions based on KSr2Nb5O15 modified electrode

In the work described by this paper, we studied the development of a selective potassium ion sensor constituted of a carbon paste electrode modified (CPEM) with a novel KSr2Nb2O15. The material KSr2Nb2O15 is an oxide with the tetragonal tungsten bronze structure (TTB) type are in forefront both in the area of research as well as in industrial applications. The sensor response to potassium ions was linear in the concentration range 1.26 x 10-5 at 1.62 x 10-3 mol L-1 (E (mV) = 32.7 + 51.1 log [K+]). The sensor based KSr2Nb2O15, of the TTB-type presented very good potentiometric response, with a slope of 51.1 mV/dec (at 25 °C) and detection limit for the potassium ions of 7.27 x 10-5 mol.L-1.