Detection of allura red based on the composite of poly (diallyldimethylammonium chloride) functionalized graphene and nickel nanoparticles modified electrode

• A novel electrochemical sensor was fabricated by PDDA-Gr-Ni composite.
• Big surface area and rapid electron transfer of Gr and Ni NPs increase sensitivity.
• The sensor was developed for determination of allura red.
• The sensor showed high sensitivity and was successfully applied in soft drinks.

A novel and sensitive electrochemical sensor for allura red determination was developed based on poly (diallyldimethylammonium chloride) (PDDA) functionalized graphene (Gr) and nickel nanoparticles (Ni) composite (PDDA-Gr-Ni). Allura red displayed remarkably increased electrochemical activity on PDDA-Gr-Ni composite modified electrode due to the synergistic effect of the large surface area and improved electron transfer efficiency of both Gr and Ni nanoparticles, which offers the feasibility for highly sensitive determination of allura red by electrochemistry method. The electrochemical properties of allura red on the modified electrode were investigated by cyclic voltammetry and differential pulse voltammetry. Under the optimum experimental conditions, the peak current of allura red was proportional to its concentration in the range of 0.05–10.0 μmol L−1 and the limit of detection (LOD) was 8.0 nmol L−1. This simple and sensitive sensor was successfully applied to determine allura red in real sample, which provides an operational access to allura red detection in the field of food safety control.