Bonney's blue paint BP 1980

This review highlights recent advancements in the development of environmentally sustainable and reliable methods for the bio-fabrication of binary metal oxide nanomaterials through plant extract-mediated green methods, with a particular emphasis on Moringa oleifera. Known for its rich profile of bioactive compounds, including vitamins, flavonoids, and phenolic acids, it serves as a natural reducing, capping, and chelating agent, facilitating the formation of bimetallic oxide nanostructures (zinc cobalt, zinc iron, and zinc zirconate) through bio-fabrication processes. The plant-derived agents from M. oleifera enhance nanomaterial properties, including catalytic activity, stability, and surface area, making them highly suitable for diverse applications in environmental remediation, biomedicine, energy, and sensing technologies. The motivation for this strategy arises from the necessity for eco-friendly, cost-efficient, and scalable techniques that reduce toxicity and eliminate hazardous chemicals. The review elaborates on the mechanisms underlying the formation of bimetallic oxide nanostructures, specifically zinc cobalt (ZnCo2O4), zinc iron (ZnFe2O4), and zinc zirconate (ZnZrO3), through chemical reactions between salt precursors and bioactive compounds extracted from M. oleifera plant natural extract. It emphasizes the principles of green synthesis that align with sustainable nanotechnology, promoting reduced toxicity and cost-effectiveness. This approach addresses the increasing demand for eco-friendly synthetic pathways utilizing plants like M. oleifera, microorganisms, and other biological sources, thereby advancing green chemistry and enabling the development of nanomaterials with enhanced functionalities for practical applications.

Abstract licence: CC BY

Pollution of water resources with hazardous substances of anthropogenic origin (e.g., synthetic dyes, heavy metal ions) is currently one of the most important environmental issues, and the development of not only effective and economical but also eco-friendly methods of removing these substances from aqueous solutions is one of the greatest challenges. Among the various separation methods, techniques based on the utilization of different types of polymer membranes have gained increasing interest due to their usually high efficiency, the materials' stability and reusability, and the possibility of using "green" components for their formation. Recent research efforts have been concentrated, inter alia, on the application of natural polysaccharide polymers (e.g., cellulose, alginates, starch, cyclodextrins) and their derivatives to produce well-performing membranes. Appropriately composed polysaccharide-based membranes under optimal process conditions enable effective separation of dyes, salts, and metal ions (e.g., often with a rejection rates of >95% for dyes and metal ions and <7% for salts). This review concerns the latest developments in the formation and utilization of novel polysaccharide-based membranes for the separation of synthetic dyes and metal ions from aqueous solutions and suspensions, with emphasis on their most important advantages, limitations, and potential impact on the environment and sustainability.

Abstract licence: CC BY

The worldwide textile industry extensively uses azo dyes, which pose serious health and environmental risks. Effective cleanup is necessary but challenging. Developing bioremediation methods for textile effluents will improve color removal efficiency. The recent attention to effectively utilizing microbes to convert toxic industrial azo dyes into non-hazardous compounds has garnered significant attention. In the present study, four fungal strains-Aspergillus flavus, Aspergillus terreus, Aspergillus niger, and Fusarium oxysporium-were employed to screen for the degradation and detoxification of azo dyes including congo red, crystal violet, bromophenol blue, and malachite green. After eight days, A. flavus had degraded azo dyes at the maximum proportion. The maximum decolorization (%) was achieved at 50 mg/L of dye concentration, 8 days of incubation, pH 6, 30 °C temperature, sucrose as a carbon source, NaNO3 as a nitrogen source, Ca+2 as minerals, and using static culture. The efficient production of laccases, lignin peroxidase, and manganese peroxidase enzymes by A. flavus proved that the enzyme played a crucial role in decolorizing the harmful azo dyes. The Fourier Transform Infrared spectrometer (FT-IR) data validated the decolorization and degradation process brought on by absorption and biodegradation. Compared to control plants, the results of the phytotoxicity assay showed that the degraded product was less harmful to maize and common bean plant's growth and germination rates. As a result, the findings indicate that A. flavus is a viable option for remediating azo dyes. This aids in the biodegradation of azo dyes found in wastewater.

Abstract licence: CC BY

A viability test for in vitro cultures, based on the intake of the textile dye alphazurine A by dead cells and its exclusion by viable cells, is described. This test uses the affinity of alphazurine A for proteins, so that the dye is retained in dead cells even after rinsing, while its anionic character prevents it from entering live cells. This feature makes this dye exclusion test amenable to a reading in a plate format. The alphazurine viability test provides an indicator of the absolute number of dead cells present in the culture well. To reach a cell viability index, a "dead cells" control (e.g. cells killed with ethanol) must be added. We also describe a double viability test, which first uses the alphazurine assay to provide the number of dead cells then a crystal violet assay to provide an index of the number of cells present in the plate. This double test provides a complete appraisal of the situation in the cell culture wells, and has been compared to other viability tests such as propidium iodide exclusion or tetrazolium reduction. Its performances to study the toxicity of substances such as pigments are also established, and allowed us to publish the first public toxicological data on the recently described Pigment Blue 86.

Abstract licence: CC BY-NC

Water is crucial for life. Being the world's third-largest industry, the textile industry pollutes 93 billion cubic meters of water each year. Only 28% of textile wastewater is treated by lower- to middle-income countries due to the costly treatment methods. The present work demonstrates the utilization of surface oxygen defects and nanopores in Mg0.8Li0.2Fe2O4 (Li-MgF) to treat textile effluents by a highly economical, scalable, and eco-friendly process. Nanoporous, oxygen-deficient Li-MgF splits water by a nonphotocatalytic process at room temperature to produce green electricity as hydroelectric cell. The adsorbent Li-MgF can be easily regenerated by heat treatment. A 70-90% reduction in the UV absorption intensity of adsorbent-treated textile effluents was observed by UV-visible spectroscopy. The oxygen defects on Li-MgF surface and nanopores were confirmed by X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller (BET) measurements, respectively. To analyze the adsorption mechanism, three known organic water-soluble dyes, brilliant green, crystal violet, and congo red, were treated with nanoporous Li-MgF. The dye decolorization efficiency of Li-MgF was recorded to be 99.84, 99.27, and 99.31% at 250 μM concentrations of brilliant green, congo red, and crystal violet, respectively. The results of Fourier transform infrared (FTIR) spectroscopy confirmed the presence of dyes on the material surface attached through hydroxyl groups generated by water splitting on the surface of the material. Total organic carbon analysis confirmed the removal of organic carbon from the dye solutions by 82.8, 77.0, and 46.5% for brilliant green, Congo red, and crystal violet, respectively. Based on the kinetic and isotherm models, the presence of a large number of surface hydroxyl groups on the surface of the material and OH- ions in solutions generated by water splitting was found to be responsible for the complete decolorization of all of the dyes. Adsorption of chemically diverse dyes by the nanoporous, eco-friendly, ferromagnetic, economic, and reusable Li-MgF provides a sustainable and easy way to treat textile industry effluents in large amounts.

Abstract licence: CC BY-NC-ND

Compared to the standard methods for treating bacterial diseases, bacteriophages are eco-friendly and chemical-free. Exposure to ultraviolet (UV) light or sunlight hampers the efficacy of phage-based approaches. This is crucial when phages are i) exposed to sunlight (e.g., in agriculture) or ii) are to be used simultaneously with UV for sterilization. Here, we develop a method utilizing a food dye, brilliant blue FCF (BB), that selectively stabilizes bacteriophages against exposure to UV irradiation. In the absence of BB, all tested phages and bacteria are completely inactivated by UV exposure. However, with the addition of BB, all tested non-enveloped phages are effectively protected, while gram-negative bacteria remain vulnerable to UV inactivation. The mechanism of protection requires selective binding of BB to the virion. The simultaneous action of BB-stabilized bacteriophages and UV allows for the removal of up to 99.99 % of bacteria within only 30-60 min. We demonstrate the method's applicability in combating biofouling of membranes and food sterilization. We envision using the developed approach against biofouling in industrial processes, agriculture, and the food industry.

Abstract licence: CC BY-NC-ND

Biochemical synthesis of nanoparticles (NPs) using plant part extracts as capping and reducing agents has drawn considerable attention in research with a growing focus on green chemistry. The present study utilized Sapota (Manilkara zapota L.) peel extract to synthesize silver nanoparticles (SP-AgNPs) using ultrasonic vibration. Different characterization techniques such as UV-vis spectroscopy, dynamic light scattering, Fourier Transform Infrared Spectroscopy, Field emission scanning electron microscope, High resolution transmission electron microscopy, and X-ray diffraction were employed to check the production of SP-AgNPs. The AgNPs were crystalline in nature and had an average particle size of 27.906 nm. The research primarily focused on two aspects: the catalytic activity of SP-AgNPs in degrading environmental pollutants and their ability to act as colorimetric sensors for toxic metal ions. SP-AgNPs exhibited significant catalytic activity in the decomposition of various pollutants such as Methyl Orange (0.035 ± 0.090 min-1, 92.89 ± 1.79%), Crystal Violet (0.1097 ± 0.1016 min-1, 85.56 ± 2.21%) and Cosmic Brilliant Blue G-250 (0.0697 ± 0.0275 min-1, 79.56 ± 1.80%). The high degradation percentages and reaction rate constants indicate the efficiency of SP-AgNPs in pollutant degradation. Additionally, the study demonstrated the effectiveness of SP-AgNPs as sensors for detecting toxic metal ions, particularly Co2+ and Hg2+ with limits of detection 54.40 ± 1.43 µM and 10.70 ± 0.16 µM. With impressive sensitivity and low detection limits, SP-AgNPs showed promise in detecting these ions, which are often found in environmental contaminants. Moreover, their plant-based synthesis, low toxicity, and cost-effectiveness make them attractive options for environmental remediation efforts.

Abstract licence: CC BY-NC-ND

BACKGROUND: Biofilm formation is an important strategy for coping with antimicrobial agents and worsening bacterial infections. In this investigation, we synthesized berberine-zinc oxide-loaded chitosan nanoparticles (CS-ZnO-Ber NPs) and explored their potential as anti-biofilm agents against Pseudomonas aeruginosa PAO1. RESULTS: CS-ZnO-Ber NPs exhibited an amorphous structure with particle sizes ranging from 34.7 to 407.7 nm and a zeta potential of − 38.5 mV. The biofilm inhibitory activity of the fabricated NPs was validated using a crystal violet staining assay. Based on the SEM imaging, cells treated with NPs displayed thin biofilms with low aggregation, whereas the untreated group exhibited robust biofilms with dense architecture. Moreover, at sub-inhibitory concentration of CS-ZnO-Ber NPs, the production levels of extracellular matrix components, including exopolysaccharides, pellicle, and alginate, decreased by 92.81 ± 0.84%, 81.45 ± 3.1%, and 31.74 ± 2.91%, respectively. Additionally, exposure to CS-ZnO-Ber NPs resulted in a significant reduction in pyocyanin production and attenuation of bacterial motility, including swimming, swarming, and twitching. CS-ZnO NPs and CS-ZnO-Ber NPs also decreased the EtBr MIC four-fold and eight-fold, respectively, indicating their efflux pump–inhibitory activity. Furthermore, molecular docking simulations revealed a favorable binding orientation of berberine with biofilm-associated proteins (AlgD, PelD, and PslG), as well as with quorum-sensing regulators LasI and LasR. CONCLUSION: Overall, CS-ZnO-Ber NPs substantially diminished extracellular matrix components, leading to the formation of weak and unstable biofilms. Pending further investigation, these findings suggest that CS-ZnO-Ber NPs hold promise as effective agents for controlling biofilm-related infections caused by P. aeruginosa.

Abstract licence: CC BY-NC-ND