Potentiometric response of calix[4]pyrrole liquid membrane electrode towards neutral nitrophenols

Calix[4]pyrroles were applied as a new class of ligands of potentiometric s ensors for neutral nitrophenol isomers. Calix[4]pyrrole-containing liquid m embranes exhibit a very high affinity to proton uptake. These membranes, in protonated form, showed very high selectivity towards para-nitrophenol in the presence of other nitrophenols and dihydroxybenzene isomers. The probab le mechanism of the potentiometric signal generation of the membrane invest igated upon stimulation by nitrophenol isomers existing in neutral form is discussed.