POTENTIOMETRIC PH SENSORS BASED ON CHEMICALLY-MODIFIED ELECTRODES WITH ELECTROPOLYMERIZED METAL-TETRAAMINOPHTHALOCYANINE

Potentiometric pH sensors based on polymer film were prepared by elect ropolymerization of the monomer nickel(II)-4,4',4 '', 4'''-tetraaminop hthalocyanine (NiTAPc) or copper(II)-4,4',4 '', 4'''-tetraaminophthalo cyanine (CuTAPc) on glassy carbon (GC) electrodes. The polymer of meta l tetraaminophthalocyanine (p-MTAPc) film coated electrodes show a slo pe of 55 +/- 1 mV/pH (at 20 degrees C) and nearly Nernstain potentiome tric response to pH over the range of pH 1-13. The electrodes possess good potential reproducibility and high selectivity, and are useful se nsing devices in pH determination and end-point indication of acid-bas e potentiometric titration. (C) 1997 Elsevier Science B.V.