Development of a novel nitrite amperometric sensor based on poly(toluidine blue) film electrode

Abstract

A novel sensor for the determination of nitrite anion ( % MathType!MTEF!2!1!+- % feaaeaart1ev0aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHX % garmWu51MyVXgatuuDJXwAK1uy0HwmaeHbfv3ySLgzG0uy0Hgip5wz % aebbnrfifHhDYfgasaacH8qrps0lbbf9q8WrFfeuY-Hhbbf9v8qqaq % Fr0xc9pk0xbba9q8WqFfea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qq % Q8frFve9Fve9Ff0dmeaabaqaciGacaGaaeqabaWaaeWaeaaakeaaca % qGobGaae4tamaaBaaaleaacaqGYaaabeaakmaaCaaaleqabaGaeyOe % I0caaaaa!3B39! $$ {\text{NO}}_{{\text{2}}} ^{ - } $$ ) was fabricated by electrodeposition of toluidine blue. The sensor exhibited good catalytic activity toward the electrochemical oxidation of nitrite. Amperometry was carried out to determine the concentration of % MathType!MTEF!2!1!+- % feaaeaart1ev0aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHX % garmWu51MyVXgatuuDJXwAK1uy0HwmaeHbfv3ySLgzG0uy0Hgip5wz % aebbnrfifHhDYfgasaacH8qrps0lbbf9q8WrFfeuY-Hhbbf9v8qqaq % Fr0xc9pk0xbba9q8WqFfea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qq % Q8frFve9Fve9Ff0dmeaabaqaciGacaGaaeqabaWaaeWaeaaakeaaca % qGobGaae4tamaaBaaaleaacaqGYaaabeaakmaaCaaaleqabaGaeyOe % I0caaaaa!3B39! $$ {\text{NO}}_{{\text{2}}} ^{ - } $$ . A linear response in the range from 1.0×10−7 to 1.52×10−5 M with a substantially low detection limit of 5×10−8 M (S/N=3) was obtained. The proposed sensor had a feature of high sensitivity of 4.7×105 μA M−1 cm−2. The possible interference from several common ions was tested. This sensor was applied to the amperometric determination of nitrite in food samples, and the results were consistent with those obtained with the standard spectrophotometric procedure.