Review—Recent Trends on the Electrochemical Sensors Used for the Determination of Tartrazine and Sunset Yellow FCF from Food and Beverage Products

Synthetic dyes were widely used in food industry due to the advantages offered, such as good stability to oxygen, light, and pH, reproducibility, bright color, low sensitivity to storage conditions and technological processing, and of course, low cost. Unfortunately, some of them have potential harmful effects on human health (the presence of azo group in the molecular structure of azo dyes has carcinogenic and mutagenic effects in the human health), thus, their detection in various food and beverage products became essential. This review presents the latest development in sensors design used for the determination of two commonly used azo dyes – tartrazine and sunset yellow in real food and beverage samples, revealing that there is a variety of efficient sensors with low limits of detection, wide linear concentration ranges, and high selectivities and sensitivities.

Photophysics and Electrochemistry of Biomimetic Pyranoflavyliums: What Can Bioinspiration from Red Wines Offer?

Natural dyes and pigments offer incomparable diversity of structures and functionalities, making them an excellent source of inspiration for the design and development of synthetic chromophores with a myriad of emerging properties. Formed during maturation of red wines, pyranoanthocyanins are electron-deficient cationic pyranoflavylium dyes with broad absorption in the visible spectral region and pronounced chemical and photostability. Herein, we survey the optical and electrochemical properties of synthetic pyranoflavylium dyes functionalized with different electron-donating and electron-withdrawing groups, which vary their reduction potentials over a range of about 400 mV. Despite their highly electron-deficient cores, the exploration of pyranoflavyliums as photosensitizers has been limited to the “classical” n-type dye-sensitized solar cells (DSSCs) where they act as electron donors. In light of their electrochemical and spectroscopic properties, however, these biomimetic synthetic dyes should prove to be immensely beneficial as chromophores in p-type DSSCs, where their ability to act as photooxidants, along with their pronounced photostability, can benefit key advances in solar-energy science and engineering.

Dyeing of Jute Fabrics with Prodigiosin Produced from Sago Waste and their Applications

Synthetic dyes are hazardous to the environment and humans due to their toxic and recalcitrant nature. Hence, the present study attempts to produce eco-friendly dye from the sago industrial waste using S. marcescens SS1. The dye produced by the bacterial bioconversion of sago was characterized by GC-MS and obtained 13.423 acquisition time, which is similar to the standard prodigiosin. The effects of the dyeing parameters were optimized for Jute fabric using tannic acid as a pre mordant, the maximum uptake of dye was observed at 80 °C, pH 7, 60 mins with the K/S of 6.6. The minimum K/S value of 3.9 was observed at 65 °C, pH 3 in 45 min. Better colour fastness was observed in prodigiosin with mordant compared to without mordant. The antimicrobial activity of dyed fabric was tested against a few pathogenic bacteria and it showed maximum activity against P. aeruginosa. The dye extracted from S. marcescens SS1 prodigiosin was found to be an effective dyeing agent and also pose antimicrobial properties.

Determination of rice husk activated Carbon capacity in adsorption of Cu Metal from Sasirangan liquid waste based on isotherm model

The process of manufacturing Sasirangan - a traditional fabric of South Kalimantan - has an impact that affects environmental pollution, namely the dyeing process of the fabric. The synthetic dyes used contain heavy metals and one of those toxic metals is copper (Cu). This study aims to determine the adsorption capacity of rice husk activated carbon adsorbent by adjusting the adsorption pattern based on isotherm models as the treatment to sasirangan liquid waste. The method consists of three stages: preparation of adsorbent by carbonization process, chemical and physical activation, then continued by adsorption process of Cu metal with carbon from rice husks with variations of adsorbent dose (2, 4, and 6 grams). This treatment was conducted by batch process. In this reseach, the adsorption capacity of rice husk adsorbent towards heavy metal Cu in sasirangan liquid waste was determined from the equilibrium state with the Langmuir isotherm equation and Freundlich isotherm equation. Based on isothermal studies of adsorption data, the correlation coefficient values obtained from the isotherm model approaches are: for dose of 2 grams adsorbent, Langmuir R2 = 0.9991 and Freundlich R2 = 0.9981; for dose of 4 grams adsorbent, Langmuir R2 = 0.9992 and Freundlich R2 = 0.9989; for dose of 6 grams adsorbent, Langmuir R2 = 0.9990 and Freundlich R2 = 0.9986. The results of investigation indicate that adsorption data correlated well with Langmuir isotherm model.

Toxicity of Legiayu incense as Insecticide and Larvicide Against Aedes aegypti Mosquitoes Mortality

Community-based DHF vector control has been implemented in Indonesia but has not yet obtained optimal results. Thus, in the community choosing synthetic insecticides to control disease vectors. However, irregular and excessive use of insecticides has a toxic effect and resistance to mosquitoes. Burning mosquito coils and incense containing synthetic dyes and fragrances have the potential to reduce environmental quality. Therefore, this research was conducted to analyze the toxicity of Legiayu incense as an insecticide and larvicide against Aedes aegypti mosquito mortality. The research design is experimental with a completely randomized design. Testing was conducted by providing exposure to smoke and ash of Legiayu incense five times on twenty-five Aedes aegypti mosquitoes. Statistical analysis used one-way ANOVA, LSD, and probit test. The test result as insecticide value (p=0.000) effective exposure for 20 minutes with a durability of 6 hours. The test result as larvicide value (p=0.000) effective exposure for 24 hours. Thus, exposure toismoke and ash of iLegiayuiincense has a very noticeable effect on the mortality of Aedes aegypti mosquitoes. Exposureito Legiayu incense smoke obtained an LT50 value of 0,9012 ≤ 5 (super toxic category) with a time of 15 minutes 39 seconds, coefficient determination of 99.24%, and correlation coefficient of 99.62% while exposure to the ash of Legiayu incense obtained LT50 value of 0,05896 ≤ 5 (super toxic category) with time 19 hours 15 minutes 34 seconds, coefficient determination and correlation coefficient of 100%. Histopathological test results showed that Legiayu incense smoke did not cause tissue degeneration, necrosis, hyperplasia, and metaplasia in the lung tissue of mice (mus musculus) within a period of 12 weeks. Thus, Legiayu incense is effective as insecticides and larvicides against Aedes aegypti mosquitoes. Legiayu incense has potential substitute for mosquito repellent coils, temephos, and synthetic incense circulating in the market.

Utilization of Andong Leaf Extract (Cordyline fruticosa) as an Alternative for Coloring the Eggs of Intestinal Nematode

Microscopic examination is essential to find the type of worm that causes infection. Direct examination of worm eggs needs to use staining to distinguish between worm eggs and food residues that are not completely digested. The dyes commonly used are synthetic. The purpose of this study was to replace synthetic dyes with natural dyes with Andong (Cordyline Fruticosa) leaf juice. It can be used as an alternative or a substitute for dyes. This research method is descriptive, conducted at the Parasitology Laboratory of Poltekkes Kemenkes Pontianak. The population in this study was the juice of the leaves of Andong (Cordyline Fruticosa). The method of inspection is direct preparation with an object glass as is routinely done, but the dye is replaced with Andong leaf juice (Cordyline Fruticosa). The results showed that natural dye Andong leaf juice (Cordyline Fruticosa), gave a clear color to the absorption of intestinal nematode worm eggs as the test target. This study concludes that the juice of the leaves of Andong (Cordyline Fruticosa) with alcohol solvent can be used as an alternative dye for the examination of intestinal nematode worm eggs.

Synthesis, application, and antibacterial activity of new direct dyes based on chromene derivatives

Aim: The goal of this study is to synthesise, analyse, and employ two new direct dyes based on chromenes derivatives as the chromophoric moiety in dyeing wool, silk, and cotton, with good colour strength, light fastness, and other desirable features. Background: The quest for new direct dyes with antimicrobial qualities for Gram-positive, Gram-negative bacteria, and fungus is underway. These dyes are commonly used on cotton, silk, and wool materials, which have great light fastness, washing, rubbing, and sweating fastness. Methods: Antibacterial activity has been measured for all dyeing fabrics. The parent structure 1 has been synthesized previously as part of the experiment. Then, these dyes are prepared by diazotization followed by coupling reaction, Results and Discussion: The p-Aminobenzenesulfonic acid (C1) and 4-Aminoazobenzene-3,4'-disulfonic acid (C2) are diazotized in hydrochloric acid with sodium nitrite, then coupled with compound 1 in a molar ratio (1: 1) at 250C until the pH is fixed at 5. Finally, the monoazo and diazo direct dyes (D1 and D2) are created. Conclusion: Wool, silk, and cotton materials benefit from the synthetic dyes' increased antibacterial action and dyeing qualities (exhaustion and fixing). They also offer better fastness qualities (light, rubbing, and perspiration).

Design and Engineering of an Efficient Peroxidase Using Myoglobin for Dye Decolorization and Lignin Bioconversion

The treatment of environmental pollutants such as synthetic dyes and lignin has received much attention, especially for biotechnological treatments using both native and artificial metalloenzymes. In this study, we designed and engineered an efficient peroxidase using the O2 carrier myoglobin (Mb) as a protein scaffold by four mutations (F43Y/T67R/P88W/F138W), which combines the key structural features of natural peroxidases such as the presence of a conserved His-Arg pair and Tyr/Trp residues close to the heme active center. Kinetic studies revealed that the quadruple mutant exhibits considerably enhanced peroxidase activity, with the catalytic efficiency (kcat/Km) comparable to that of the most efficient natural enzyme, horseradish peroxidase (HRP). Moreover, the designed enzyme can effectively decolorize a variety of synthetic organic dyes and catalyze the bioconversion of lignin, such as Kraft lignin and a model compound, guaiacylglycerol-β-guaiacyl ether (GGE). As analyzed by HPLC and ESI-MS, we identified several bioconversion products of GGE, as produced via bond cleavage followed by dimerization or trimerization, which illustrates the mechanism for lignin bioconversion. This study indicates that the designed enzyme could be exploited for the decolorization of textile wastewater contaminated with various dyes, as well as for the bioconversion of lignin to produce more value-added products.

Graphene Oxide Embedded Copper Composite as an Efficient Mordant to Enhance the Properties of Natural Dye Coated Cotton Fabric.

In the textile sector, the utilization of synthetic dyes is environmentally unfriendly and has a very harmful impact on human health and the environment. Hence, natural dye is assumed to be a suitable alternative for sustainable textile manufacturing and colouration, but it remains challenging to prepare the dyes having high stability with textile fablric. Herein we have demonstrated the dyeing process for cotton fabric with natural dye extractions from turmeric (Curcuma longa L.) and tea (Camellia sinensis) in the presence of mordant. Subsequently, we have prepared copper and 2-methyl 8-hydroxyquinoline functionalized graphene oxide (GO) (CHG) trinary-composite as mordant to improve the stability and colour strength of naturally extracted dyes. The prepared trinary-composite was investigated using various techniques such as FTIR, XRD, UV, and TGA analysis. To evaluate the effect of CHG composite, it mixed with natural extracted dyes such as turmeric and tea dyes, converted to CHG functionalized turmeric and tea dyes (TuCHG and TeCHG) for the dyeing of cotton fabric. TuCHG and TeCHG dyed cotton fabrics exhibited superior colourfastness, wash fastness and rub fastness in comparison to only turmeric and tea dyes dyed cotton fabrics. TuCHG and TeCHG dyes also demonstrated decent antibacterial properties. The present study indicates the new aspect for prepared mordant to increase natural dye colour strength and stability. Thus, this process is a much safer, cost-effective and sustainable method for the application of natural dyes with enhanced substantively for cotton fabric.