An ultrasensitive electrochemical platform based on copper oxide nanoparticles and poly (crystal violet) for the detection of brilliant blue FCF from soft drinks

[Display omitted] •Fabrication of a novel electrochemical platform for brilliant blue detection.•Platform based on poly (crystal violet) and copper oxide nanoparticles.•Picomolar detection limit and very sensitive brilliant blue detection.•The designed platform exhibits high sensitivity and excellent reproducibility.•The platform was successfully applied to detect brilliant blue in real samples. In this study, a highly sensitive and quick electrochemical platform based on poly (crystal violet) film and copper oxide nanoparticles for the detection of brilliant blue FCF from various soft beverages was developed. The synthesized copper oxide nanoparticles were investigated with Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray. Further, crystal violet was electropolymerized on the surface of the carbon paste electrode modified with copper oxide nanoparticles. The electrochemical properties of poly (crystal) violet/copper oxide nanoparticles modified carbon paste electrode were assessed through the utilization of cyclic voltammetry and electrochemical impedance spectroscopy. Furthermore, the signal towards the oxidation of brilliant blue was examined using the differential pulse voltammetry method. Under ideal experimental conditions, the peak current exhibited a linear relationship with the brilliant blue concentration within the range of 0.01–1.00 nmol/L, with a sensitivity of 294.55 µA nmol/L cm−2 and a significant detection limit of 3 pmol/L. In the presence of other dyes and other food additives, the developed platform showed greater selectivity in detecting brilliant blue. The reliability of the designed platform was demonstrated by the 99.19 – 100.67 recovery percentage for the identification of BB in various soft drink samples.