A Novel Thiocyanate-Selective Membrane Sensors Based on Salicylaldehyde-O-Aminophenol Binuclear Copper (II) Complex as a Neutral Carrier

Abstract

A new potentiometric thiocyanate-selective membrane sensor based on salicyladehyde-o-aminophenol binuclear copper (II) [Cu2(II)-SOA] complex as a neutral carrier is reported, which displays a preferential potentiometric response to thiocyanate ion and an anti-Hofmeister selectivity sequence in the following order: SCN- > Sal- > ClO4- > I- > NO2- > Br- > Cl- > NO3- > SO32- > H2PO4- > SO42- . The sensor exhibits a near-Nernstian potential over a wide linear range of 6.0×10-7 - 1.0×10-1 M with a detection limit of 2.0×10-7 M and a slope of –56.2 mV/decade in pH 4.0 of a phosphate buffer solution at 20 °C.