Amperometric nitric oxide sensor based on nanoporous platinum phthalocyanine modified electrodes

Abstract

This article describes the fabrication of electropolymerized Metallo 4′, 4″, 4ấ, 4′′′′ tetra-amine phthalocyanine (poly-MTAPc) modified electrodes for the detection of nitric oxide (NO) in phosphate-buffered saline (PBS) at pH 7.4. A two-step synthetic protocol using a laboratory microwave reactor was adopted to provide three MTAPc complexes bearing different metal centers (M = Cu2+: CuTAPc, M = Zn2+: ZnTAPc, and M = Pt2+: PtTAPc). The MTAPc complexes and the intermediates were characterized by MALDI-TOF mass spectrometry, UV-vis spectroscopy, 1H NMR spectroscopy, and elemental analysis. The MTAPc products were separately electropolymerized either onto a glassy carbon (GC) electrode as a thin-film or within the pores of Anodisc nanoporous alumina membrane as a densely packed array of poly-MTAPc nanotubes to produce two electrode systems. In the latter system, the surface area enhancement provided by the nanotube-arrayed morphology of the poly-MTAPc enabled a high faradaic (signal) to capacitative (background) current during NO electro-oxidation. Amperometric detection of NO using these two electrode systems shows that the sensitivity and linear ranges were insensitive to the metal centers (M = Cu 2+, Zn2+, and Pt2+) of the poly-MTAPc material. © 2012 American Chemical Society.