Ion-exchange reaction of silver(I) and copper(II) in optical sensors based on thiaglutaric diamide.

Bulk optode membranes based on a recently reported thiaglutaric diamide ionophore were developed for measurements of silver(I) and copper(II) ions in aqueous solutions. The response properties of optical films containing ionophore and chromoionophores with different pK(a) values were investigated at different sample pH. At certain pH the measuring range of the optode can be shifted when choosing different chromoionophores. Optode with ionophore and chromoionophore V exhibited good responses to silver ions from 10(-6)-10(-1) M at pH 5.5. The proposed sensor showed high selectivity, good reproducibility and stability. With a different chromoionophore ETH 5418 the optode could response to copper(II) ions from 10(-6)-10(-2) M.