Rapid and simple electrochemical approximation for the determination of the food additive amaranth using voltammetric sensor

This study reports the fabrication of a novel voltammetric platform based on the modification of screen printed gold electrode (SPGE) with palladium and copper (Pd-Cu) bimetallic microparticles. The novel platform (Pd-Cu/SPGE) was applied for the voltammetric determination of amaranth in fruit soda, orange juice, and tap water. The modified electrode was characterized using scanning electron microscopy, electrochemical impedance spectroscopy, and cyclic voltammetry. The electrode surface area of the Pd-Cu/SPGE is about two times larger than that of the SPGE. Differential pulse voltammetry was used to determine the amaranth. The chromatographic method was preferred for the reference method. At the optimal parameters, the anodic peak current of amaranth was found to be linearly dependent on its concentrations ranging from 0.002 to 15.00 µM. The detection limit was 0.5 nM (S/N = 3). For the analysis of amaranth, 101.16–104.33% of recovery percentage was obtained. This highly selective and sensitive electrode supplied the fast determination of amaranth in real samples. At a 95% confidence level, the values obtained from voltammetric and chromatographic analyses are in agreement.

Graphical Abstract