Sensitive and Selective Analysis of Nigrosine Dye at Polymer Modified Electrochemical Sensor

Glycine was used to fabricate a modified electrode, as a highly sensitive voltammeric sensor and was used for the determination of Nigrosine (NG) in 0.2 M phosphate buffer solution (PBS) having pH 6.0. A fast and easy method for the fabrication of polyglycine modified carbon paste electrode (PGMCPE) by cyclic voltammetry was used. The resulted modified electrode shows superior electrocatalytic activity towards the oxidation of NG compare with (BCPE) in 0.2 M PBS at 6.0 pH. The electrode surfaces were characterized by Field emission scanning electron microscopy (FESEM). The effect of various experimental parametrers on the voltammetric response of NG were investigated. At optimum conditions, the sensor has a linear response in the concentration range of 3×10-5 to 5×10-5 M and 6×10-5 to 1×10-4 M with the limit of detection 8×10-8 M and limit of quantification 2.6×10-7 M. The modified electrode demonstrated having many advantages such as simple preparation, high sensitivity, and low detection of limit, excellent catalytic activity, and reproducibility.