A sensitive and novel electrochemical sensor for the detection of Allura Red (AR) in the presence of tartrazine (TRZ) was fabricated using a screen-printed electrode modified by functionalized nanodiamond covered using silicon dioxide and titanium dioxide nanoparticles (F-nanodiamond@SiO2@TiO2/SPE). Scanning electron microscopy (SEM), brunauer-Emmett-teller (BET), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR) techniques were performed to characterize the as-synthesized Fnanodiamond@SiO2@TiO2 nanocomposite. The as-fabricated electrode demonstrated two wide dynamic ranges of 0.01-0.12 and 0.12-8.65 μM with a limit of detection (LOD) as low as 1.22 nM. Moreover, the modified electrode exhibits excellent repeatability, reproducibility, reusability, selectivity, and stability with high sensitivity of 44.3 μA μM-1 cm-1, offering good prospects in the simple, cost-effective, and rapid assessment of their total concentration. The successful detection of AR and TRZ, simultaneously and individually in food samples, revealed the applicability of the sensor in the determination of AR and TRZ with satisfactory recovery. Therefore, these advantages provide an excellent possibility for the smart monitoring of AR and TRZ in the future. In the final step, the preferential intercalative binding mode of Allura red with ds-DNA was approved for the first time by a molecular docking study. This study paves the way for engineering highly sensitive DNA biosensors to monitor azo dye compounds by combining the benefits of nanocomposites and valuable information of a molecular docking study.
Keywords: Allura red; Azo dye; F-nanodiamond; Silicon dioxide; Titanium dioxide; Voltammetry.
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