Electrochemical Sensor Based on Poly(Sodium 4-Styrenesulfonate) Functionalized Graphene and Co3O4 Nanoparticle Clusters for Detection of Amaranth in Soft drinks

A new sensitive electrochemical sensor based on poly(sodium 4-styrenesulfonate) (PSS) functionalized graphene and Co3O4 nanoparticle clusters (PSS-GN/Co3O4) ternary composite was fabricated via two-step synthesis. The PSS-GN/Co3O4 nanocomposite significantly increased the oxidative activity of amaranth due to the individual merit and mutual effect of PSS-GN and Co3O4 nanoparticle clusters which improved the performance of the electrochemical sensor with high sensitivity. Cyclic voltammetry (CV) and linear sweep voltammetry (LSV) measurements were used for the detection of amaranth. Under the optimal conditions, the oxidation peak currents of amaranth increased proportionally to the concentration within the range of 0.01–1.0 and 1.0–6.0 μmol L−1, and the limit of detection was 4.0 nmol L−1. The proposed modified electrode was highly sensitive and was successfully applied to determine amaranth in the soft drinks with satisfactory recoveries. The as-prepared PSS-GN/Co3O4/GCE electrochemical sensor offers a feasible way for designing simpler, low cost, and environment-friendly sensors based on Co3O4 nanoparticle clusters.