Electrochemical determination of nitrite based on poly(amidoamine) dendrimer-modified carbon nanotubes for nitrite oxidation

This study describes a simple and reliable method for the electrochemical determination of nitrite based on poly(amidoamine)-modified carbon nanotubes. Amine-terminated poly(amidoamine) (generation 4.0, G4-NH4) were covalently attached onto multi-walled carbon nanotube (MWNT)-modified glass carbon (GC) electrodes (written as G4-NH4/MWNT-modified GC) and which were used for the electrochemical determination of nitrite. The studies show that the G4-NH4/MWNT-modified electrodes demonstrated significantly enhanced electrochemical activity towards nitrite oxidation. Chronoamperometry studies reveal that the amperometric response is rapid, stable, and offers a linear dependence over a wide range of nitrite concentrations from 5 mu M to 1.5 mM. The proposed method can be used for the continuous monitoring of nitrite in real samples. The electrochemical properties of the G4-NH4/MWNT nanocomposites are reasonably envisaged to be promising for providing a nanostructured platform in the development of electrochemical sensors or biosensors. (C) 2009 Elsevier B.V. All rights reserved.