Simultaneous voltammetric determination of dopamine and serotonin on carbon paste electrodes modified with iron(II) phthalocyanine complexes

Carbon paste electrodes (CPE) containing iron(II)) phthalocyanine (FePc) an d iron(II) tetrasulfophthalocyanine ([FeTSPc](4-)) were used for the detect ion of dopamine (DA) and serotonin (5-HT). Both complexes showed catalytic activity towards the detection of DA and 5-HT. The catalytic activities of [FeTSPc](4-) and FePc are compared with those of [CoTSPc](4-), [NiTSPc](4-) , CoPc and NiPc complexes and with those of metal(II)) tetraaminophthalocya nines (MTAPc, where M = Ni, Co or Fe) complexes. A significant improvement in the reversibility of the DA oxidation couple was observed on FeTSPc](4-) and FePc modified CPE. [FeTSPc](4-) and other [MTSPc](4-) modified electro des inhibited the detection of ascorbic acid (AA), a major interferent in t he detection of DA. Simultaneous detection of DA and 5-HT on [FeTSPc](4-) m odified CPE, in the presence of AA, showed that AA does not interfere with the determination of both species. Also no interference between DA and 5-HT was observed. (C) 2001 Elsevier Science B.V. All rights reserved.