A new silver(I)-selective electrode based on derivatized MWCNTs@SiO2 nanocomposites as a neutral carrier

For the first time a novel carbon paste electrode (CPE) for the detection of trace silver(I) was designed by using derivatized silica-coated multi-walled carbon nanotubes (MWCNTs@SiO2) nanocomposites as a neutral carrier. This proposed electrode, with optimum composition, exhibits a wide dynamic range of 8.6 × 10− 8 to 1.0 × 10− 1 M toward silver(I) with a detection limit of 8.0 × 10− 8 M and a Nernstian slope of 60.8 ± 0.2 mV dec− 1. Meanwhile, it also shows a good selectivity and a relatively fast response time (~ 20 s), a long lifetime (1 month) and a wide pH range (4.0–9.0). Finally, the developed CPEs were successfully applied in the potentiometric titration of potassium bromide and determination of Cl− ions in different water samples.