Amperometric sensor for nitrite using a glassy carbon electrode modified with alternating layers of iron(III) tetra-(N-methyl-4-pyridyl)-porphyrin and cobalt(II) tetrasulfonated phthalocyanine

Wilney J R Santos; Aline L Sousa; Rita C S Luz; Flavio S Damos; Lauro T Kubota; Auro A Tanaka; Sônia M C N Tanaka

doi:10.1016/j.talanta.2006.01.023

Amperometric sensor for nitrite using a glassy carbon electrode modified with alternating layers of iron(III) tetra-(N-methyl-4-pyridyl)-porphyrin and cobalt(II) tetrasulfonated phthalocyanine

Talanta. 2006 Oct 15;70(3):588-94. doi: 10.1016/j.talanta.2006.01.023. Epub 2006 Feb 21.

Authors

Wilney J R Santos¹, Aline L Sousa, Rita C S Luz, Flavio S Damos, Lauro T Kubota, Auro A Tanaka, Sônia M C N Tanaka

Affiliation

¹ Departament of Chemistry and Technology, UFMA, Avenida dos Portugueses s/n, 65085-580 São Luís, MA, Brazil.

PMID: 18970813
DOI: 10.1016/j.talanta.2006.01.023

Abstract

The development of a highly sensitive amperometric sensor for nitrite using a glassy carbon electrode modified with alternated layers of iron(III) tetra-(N-methyl-4-pyridyl)-porphyrin (FeT4MPyP) and cobalt(II) tetrasulfonated phthalocyanine (CoTSPc) is described. The modified electrode showed an excellent catalytic activity and stability for the nitrite oxidation decreasing the peak potentials about 200mV toward less positive values and presenting much higher peak currents than those obtained on the bare GC electrode. A linear response range of 0.2-8.6mumoll(-1), with a sensitivity of 0.37muAlmumol(-1) and detection limit of 0.04mumoll(-1) were obtained with this sensor. The repeatability of the proposed sensor, evaluated in term of relative standard deviation, was verified to be 1.4% for 10 measurements of 0.2mumoll(-1) nitrite solution. Interference caused by common ions has been investigated in simulated mixtures containing high concentration level of interfering ions and the sensor was found to be tolerant against these ions. The developed sensor was applied for the nitrite determination in water samples and the results were in agreement with those obtained by a comparative method described in the literature. The average recovery for these samples was 100.1 (+/-0.7)%.