Highly Sensitive and Selective Electrochemical Determination of Sunset Yellow in Food Products Based on AuNPs/PANI‐co‐PoAN‐co‐PoT/GO/Au Electrode

Construction of modified screen-printed graphite electrode for the application in electrochemical detection of sunset yellow in food samples

The current work introduced a novel electrochemical sensor (screen-printed graphite electrode (SPGE) modified with MnO₂ nanorods anchored graphene oxide nanocomposite (MnO₂ NRs/GO) for sensitive determination of sunset yellow. The characterization of MnO₂ NRs/GO nanocomposite synthesized through a simple hydrothermal approach was determined employing varied analytical equipment like Field emission-scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). Chronoamperometric measurements, differential pulse voltammetry (DPV), cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were recruited to recognize the electrochemical oxidation of sunset yellow on the MnO₂ NRs/GO/SPGE. The results of CV proved that the as-synthesized MnO₂ NRs/GO nanocomposite has a good electrocatalytic activity toward sunset yellow. The MnO₂ NRs/GO/SPGE electrode under optimized conditions using the DPV possessed a linear response for different concentrations of sunset yellow (between 0.01 and 115.0 μM) with a low limit of detection (LOD) (0.008 μM). Finally, the impressive applicability of this sensor was confirmed via real sample analysis with excellent recoveries (between 97.3 and 104.6%).

Recent advances in carbon nanomaterials-based electrochemical sensors for food azo dyes detection

Azo dyes as widely applied food colorants are popular for their stability and affordability. On the other hand, many of these dyes can have harmful impacts on living organs, which underscores the need to control the content of this group of dyes in food. Among the various analytical approaches for detecting the azo dyes, special attention has been paid to electro-analytical techniques for reasons such as admirable sensitivity, excellent selectivity, reproducibility, miniaturization, green nature, low cost, less time to prepare and detect of specimens and the ability to modify the electrode. Satisfactory results have been obtained so far for carbon-based nanomaterials in the fabrication of electrochemical sensing systems in detecting the levels of these materials in various specimens. The purpose of this review article is to investigate carbon nanomaterial-supported techniques for electrochemical sensing systems on the analysis of azo dyes in food samples in terms of carbon nanomaterials used, like carbon nanotubes (CNT) and grapheme (Gr).

Network structure-based decorated CPA@CuO hybrid nanocomposite for methyl orange environmental remediation

A unique network core-shell hybrid design-based cross-linked polyaniline (CPA), which was coated with CuO nanoparticles (NPs) and decorated with nitrogen-doped SWCNT/GO/cellulose N-SWCNTS-GO-CE, has been fabricated using the oxidative polymerization technique. This hybrid nanocomposite shows excellent photocatalytic degradation and an acceptable adsorption capability for Methyl Orange (MO) dye in aqueous solutions with a very slight effect for the N-SWCNTS-GO-CE CuO component. The prepared nanocomposites were used for the removal of a carcinogenic and noxious dye, Methyl Orange, from aqueous samples under various adsorption conditions. Approximately 100% degradation of 10 mg/L of Methylene orange dye was observed within 100 min at pH 6.0 using 50 mg/L CPA/N-SWCNTS-GO-CE/CuO nanocomposite under UV radiation. Additionally, significant factors were investigated on the degradation process including the contact time, MO initial concentration (Ci), solution pH, and dosage of the CuO nanocomposite. All investigated experiments were performed under UV radiation, which provided significant data for the MO degradation process. Furthermore, the recovery of the nanocomposite was studied based on the photocatalytic process efficiency. The obtained data provide the high opportunity of reusing CPA/N-SWCNTS-GO-CE/CuO nanocomposite for numerous photocatalytic processes. The CPA/N-SWCNTS-GO-CE/CuO nanocomposite was prepared via chemical oxidative copolymerization of polyaniline (PANI) with p-phenylenediamine (PPDA) and triphenylamine (TPA) in the presence of N-SWCNTS-GO-CE and CuO NPs. The morphology, structure and thermal properties of the CPA/N-SWCNTS-GO-CE/CuO nanocomposite were investigated using various techniques, including FTIR, XRD, RAMAN, SEM, MAP, EDX, TEM, TGA and DTG. Therefore, CPA/N-SWCNTS-GO-CE/CuO nanocomposite can be effectively used as a convenient and reusable adsorbent to remove hazardous dye from wastewater.