Effect of alumina supported on glassy-carbon electrode on the electrochemical reduction of 2,4,6-trinitrotoluene: A simple strategy for its selective detection

Abstract This work presents the low-potential electrochemical reduction of 2,4,6-trinitrotoluene (TNT) by catalytic action of alumina abrasively supported on glassy-carbon electrode (GCE). The three reduction peaks were shifted to less negative potentials with improved peak-resolution, combined with increase in current and analytical sensitivity. Adsorption of TNT on alumina particles immobilized on GCE especially in acid medium resulted in the facilitated the electron transfer process between TNT and GCE. A similar behavior was verified for other nitroaromatic compounds, such as nitrobenzene, nitrotoluene, and 2,4-dinitrotoluene; however, they did not interfere on the first reduction peak of TNT. Dissolved oxygen electrochemical reduction was also significantly enhanced by the presence of alumina but no interference on TNT detection was verified. The alumina-polished GCE provided a detection limit of 0.83 nmol L−1 within a wide linear range (0.5–1000 μmol L−1), which is comparable with graphene-based electrochemical sensors reported, free from the interference from other nitro-aromatic explosives.