Fabrication and characterization of covalently attached multilayer films containing iron phthalocyanine and diazo-resins

Highly stable covalently attached multilayer films containing diazo-resins (DAR) and iron(m) tetrasulfophthalocyanine (FeTsPc) were fabricated by an ionic self-assembly technique and a following photoreaction induced by UV irradiation. UV irradiation converted the electrostatic interaction at the interfaces into covalent bonds. These changes were further confirmed by UV-Vis spectra and FTIR spectra. Atomic force microscopy (AFM) experiments showed that the conversion of the interaction at the interfaces had increased the stability of the films dramatically. From the surface photovoltage spectra (SPS), it could be followed that the photovoltage response of the n-type silicon increased by a factor of about 5 times when modified with 6 bilayers of DAR/FeTsPc multilayer films. An electrode modified with DAR/FeTsPc multilayer films not only has stable electrochemical behavior but also can catalyse the oxidation of cysteine. A considerable reduction in overpotential for cysteine oxidation was observed.