A dual K +–Na + selective Prussian blue nanotubes sensor

A strategy for dual sensing of Na + and K + ions using Prussian blue nanotubes via selective inter/deintercalation of K + ion and competitive inhibition by Na + ion, is reported. The analytical signal is derived from the cyclic voltammetry cathodic peak position E pc of Prussian blue nanotubes. Na + and K + levels in a sample solution can be determined conveniently using one Prussian blue nanotubes sensor. In addition, this versatile method can be applied for the analysis of single type of either Na + or K + ions. The dual-ion sensor response towards Na + and K + can be described using a model based on the competitive inhibition effects of Na + on K + inter/deintercalation in Prussian blue nanotubes. Successful application of the Prussian blue nanotubes sensor for Na + and K + determination is demonstrated in artificial saliva.