Advanced Spectrophotometric Analysis of Sunset Yellow Dye E110 in Commercial Food Samples

Efficient extraction of textile dyes using reusable acrylic-based smart polymers

Water pollution from industrial or household waste, containing dyes from the textile industry, poses a significant environmental challenge requiring immediate attention. In this study, we have developed a crosslinked-smart-polymer film based on 2-(dimethylamino)ethyl methacrylate copolymerized with other hydrophilic and hydrophobic commercial monomers, and its efficacy in removing 21 different textile dyes was assessed. The smart polymer effectively interacts with and adsorbs dyes, inducing a noticeable colour change. UV-Vis spectroscopy analysis confirmed a removal efficiency exceeding 90 % for anionic dyes, with external diffusion identified as the primary influencing factor on process kinetics, consistent with both pseudo-first-order kinetics and the Crank-Dual model. Isothermal studies revealed distinct adsorption behaviors, with indigo carmine adhering to a Freundlich isotherm while others conformed to the Langmuir model. Permeation and fluorescence analyses corroborated isotherm observations, verifying surface adsorption. Significantly, our proof-of-concept demonstrated the resilience of the smart-film to common fabric softeners and detergents without compromising adsorption capacity. Additionally, the material exhibited reusability (for at least 5 cycles), durability, and good thermal and mechanical properties, with T5 and T10 values of 265 °C and 342 °C, respectively, a Tg of 168 °C, and a water swelling percentage of 54.3 %, thus confirming its stability and suitability for industrial application. ENVIRONMENTAL IMPLICATION: Dyes released during laundry processes should be classified as "hazardous materials" owing to their significant toxicity towards aquatic organisms, with the potential to disrupt ecosystems and harm aquatic biodiversity. This paper discusses the development of a novel acrylic material in film form, engineered to extract toxic anionic dyes. This study directly contributes to mitigating the environmental impact associated with the fashion industry and the domestic use of textiles. It can be implemented on both an industrial and personal scale, thereby encouraging more sustainable practices and promoting collaborative citizen science efforts towards.

Development of a highly sensitive ultra-small ratiometric fluorescence nanosphere probe for Sunset Yellow detection

A highly sensitive ultra-small ratiometric fluorescence nanosphere probe was successfully manufactured to detect Sunset Yellow (SY). The probe, CMCS@N, S-CDs/Rh6G, was formed through the encapsulation of N, S-CDs and Rh6G within carboxymethyl chitosan (CMCS) through in situ cross-linking. Remarkably, our nanosphere probe had an average grain diameter of 6.80 nm and exhibited excellent dispersibility without the need for additional solvents. The probe exhibited a strong linear relationship with SY concentration in the range of 0.26-100 μM, with a low detection limit of 0.078 μM. Furthermore, SY demonstrated strong fluorescence quenching capability on our nanosphere probe, with the fluorescence quenching mechanism involving a combined effects of inner filter effect (IFE) and static quenching. Notably, our nanosphere probe retained the bacteriostatic properties of CMCS, with a substantial bacteriostasis rate of 77.58 %, introducing novel potential applications.

Nitrogen-doped biomass-derived carbon dots for fluorescence determination of sunset yellow

Sunset Yellow (SY) is a widely used food coloring in the food industry. However, exceeding the allowable limit of this dye poses a significant threat to human health. To address this issue, we developed Lycium ruthenicum-derived nitrogen-doped carbon dots (N-CDs) with a stable blue fluorescence through hydrothermal treatment for SY determination. The quantum yield (QY) of these N-CDs was found to be up to 10.63%. Physical characterization of N-CDs was performed using various spectroscopic techniques to confirm their excellent photostability and non-toxic properties. Furthermore, the presence of SY had a substantial quenching effect on the fluorescence intensity (F0/F) of the N-CDs. Leveraging this observation, we developed a fluorescent sensor for the determination of SY in the concentration range of 0.05 to 35.0 μM, with a limit of detection (LOD, 3σ/K) of 17 nM. The excellent fluorescent sensor also showed satisfactory results in the practical drink samples. Moreover, the stability and cytotoxicity of N-CDs as a fluorescent probe were studied. Finally, the N-CDs were applied to cell imaging using A549 cells.

Voltammetric Sensor Based on the Combination of Tin and Cerium Dioxide Nanoparticles with Surfactants for Quantification of Sunset Yellow FCF

Sunset Yellow FCF (SY FCF) is one of the widely used synthetic azo dyes in the food industry whose content has to be controlled for safety reasons. Electrochemical sensors are a promising tool for this type of task. A voltammetric sensor based on a combination of tin and cerium dioxide nanoparticles (SnO2-CeO2 NPs) with surfactants has been developed for SY FCF determination. The synergetic effect of both types of NPs has been confirmed. Surfactants of various natures (sodium lauryl sulfate (SLS), Brij® 35, and hexadecylpyridinium bromide (HDPB)) have been tested as dispersive media. The best effects, i.e., the highest oxidation currents of SY FCF, have been observed in the case of HDPB. The sensor demonstrates a 4.5-fold-higher electroactive surface area and a 38-fold-higher electron transfer rate compared to the bare glassy carbon electrode (GCE). The electrooxidation of SY FCF is an irreversible, two-electron, diffusion-driven process involving proton transfer. In differential pulse mode in Britton-Robinson buffer (BRB) pH 2.0, the sensor gives a linear response to SY FCF from 0.010 to 1.0 μM and from 1.0 to 100 μM with an 8.0 nM detection limit. The absence of an interferent effect from other typical food components and colorants has been shown. The sensor has been tested on soft drinks and validated with the standard chromatographic method.

A modified electrode based on a 3D reduced graphene oxide and MoS2 composite for simultaneous detection of sunset yellow and tartrazine

A 3D reduced graphene oxide (3DrGO) composite loaded with cauliflower-like MoS2 was prepared. Benefiting from the synergistic effects of 3DrGO and cauliflower-like MoS2, a glassy carbon electrode (GCE) modified with the 3DrGO-MoS2 composite (3DrGO-MoS2/GCE) displays high sensing performance for sunset yellow (SY) and tartrazine (TZ) at working potentials of 0.795 and 1.034 V. Furthermore, a well separated oxidation peak potential can achieve simultaneous detection of the two analytes. Under selected conditions, the peak current exhibits a piecewise linear relationship with the SY concentration in the range of 0.05-10 μmol L-1 and 10-60 μmol L-1, and the plot of peak current versus the TZ concentration also exhibits two linear segments in the range of 0.1-6.0 μmol L-1 and 6.0-60 μmol L-1. The detection limits of SY and TZ are as low as 17.6 and 37.4 nmol L-1, respectively. The prepared 3DrGO-MoS2/GCE was applied for the determination of SY and TZ in food samples with excellent recoveries of 95.1-105.4%.

An Electrochemical Sensor Based on Carbon Paper Modified with Graphite Powder for Sensitive Determination of Sunset Yellow and Tartrazine in Drinks

The paper describes the development of an electrochemical sensor to be used for the determination of synthetic food colorants such as Sunset Yellow FCF (SY) and Tartrazine (TZ). The sensor is a carbon paper (CP) electrode, manufactured by using hot lamination technology and volume modified with fine-grained graphite powder (GrP). The sensor (GrP/CP) was characterized by scanning electron microscopy, energy dispersive spectrometry, electrochemical impedance analysis, cyclic, linear sweep and differential pulse voltammetry. The mechanism of SY and TZ electrochemical oxidation on GrP/CP was studied. The developed sensor has good electron transfer characteristics and low electron resistance, high sensitivity and selectivity. Applying the differential pulse mode, linear dynamic ranges of 0.005–1.0 μM and 0.02–7.5 μM with limits of detection of 0.78 nM and 8.2 nM for SY and TZ, respectively, were obtained. The sensor was used to detect SY and TZ in non-alcoholic and alcoholic drinks. The results obtained from drink analysis prove good reproducibility (RSD ≤ 0.072) and accuracy (recovery 96–104%).

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).

A portable solid-state potentiometric sensor based on a polymeric ion-exchanger for the assay of a controversial food colorant (sunset yellow)

Food additives are chemicals added to enhance the appearance, taste, or lifetime of food products. Authorities continuously update the lists of the allowed additives and their daily intake limits. Thus, authorities and food suppliers strictly monitor additives in food products to guarantee their safety and compliance with national laws and safety criteria. The daily intake of the food colorant sunset yellow is banned in some countries and strictly controlled in others. Herein, a chemically modified solid-state potentiometric sensor was fabricated and used for the direct, fast, sensitive and selective assay of sunset yellow in soft drink and pharmaceutical formulation samples. The study optimized the sensor composition and the optimized carbon paste included a novel polymeric ion-exchanger, dioctyl phthalate, chitosan, and calix-[8]-arene and produced a rapid and near-Nernstian response of -32.9 ± 0.821 mV per decade for sunset yellow in the concentration range 7.94 × 10^-5 M to 1.0 × 10^-2 M and in the pH range 5-10. The sensor revealed good selectivity toward sunset yellow in the presence of commonly encountered ionic species. The method was validated according to the International Council for Harmonization guidelines and the results were statistically comparable to those of a reported method. The solid-state sensor represents a tool for fast and direct assay of sunset yellow in food products without sample pretreatment.

Spectrophotometric determination of Metronidazole antibacterial drug via oxidation with alkaline potassium permanganate

Highly simple, sensitive and selective method is developed for the spectrophotometric determination of Metronidazole (MDZ) antibacterial drug either in pure form or in pharmaceutical formulations. This method is based on reduction of potassium permanganate by Metronidazole drug in sodium hydroxide solution to give green manganate ion which recorded at 610 nm. The method produced linear responses in the concentration range 4.28 - 59.91 µg mL^-1 with limit of detection (LOD) and limit of quantification (LOQ) 0.21 and 0.69 µg mL^-1 for Metronidazole drug respectively. The apparent molar absorptivity is 0.865 × 10⁴ L mol^-1 cm^-1, Sandell sensitivity is 0.019 µg cm^-2 and correlation coefficient is 0.951. The method is highly reproducible and has been applied to a wide variety of pharmaceutical formulations and the results compare favourably with those of official methods.

Disposable Electrochemical Sensor for Food Colorants Detection by Reduced Graphene Oxide and Methionine Film Modified Screen Printed Carbon Electrode

A facile synthesis of reduced graphene oxide (rGO) and methionine film modified screen printed carbon electrode (rGO-methionine/SPCE) was proposed as a disposable sensor for determination of food colorants including amaranth, tartrazine, sunset yellow, and carminic acid. The fabrication process can be achieved in only 2 steps including drop-casting of rGO and electropolymerization of poly(L-methionine) film on SPCE. Surface morphology of modified electrode was studied by scanning electron microscopy (SEM). This work showed a successfully developed novel disposable sensor for detection of all 4 dyes as food colorants. The electrochemical behavior of all 4 food colorants were investigated on modified electrodes. The rGO-methionine/SPCE significantly enhanced catalytic activity of all 4 dyes. The pH value and accumulation time were optimized to obtain optimal condition of each colorant. Differential pulse voltammetry (DPV) was used for determination, and two linear detection ranges were observed for each dye. Linear detection ranges were found from 1 to 10 and 10 to 100 µM for amaranth, 1 to 10 and 10 to 85 µM for tartrazine, 1 to 10 and 10 to 50 µM for sunset yellow, and 1 to 20 and 20 to 60 µM for carminic acid. The limit of detection (LOD) was calculated at 57, 41, 48, and 36 nM for amaranth, tartrazine, sunset yellow, and carminic acid, respectively. In addition, the modified sensor also demonstrated high tolerance to interference substances, good repeatability, and high performance for real sample analysis.