Investigating the pH range of a modified carbon nanotube sensor based on N-quinoline-2-carboxamido-8-aminoquinoline

Potentiometric monitoring of metal ions based on ion selective electrodes (ISEs) offer the advantages of speed and ease of preparation and procedures, relatively fast responses, reasonable selectivity thorough judicious choice of the membrane active materials, wide linear dynamic range, and very low cost. In this work, we wish to introduce a highly selective and sensitive Ho3+ ion-selective membrane electrode by incorporation of N-quinoline-2-carboxamido-8-aminoquinoline (QCA) as an ionophore, carbone nano tube and nano silica as modifier, paraffin oil as binder in a carbon paste electrodes (CPEs). The potentiometric response is independent of pH in the range of 3.8 - 9.3 .