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In this study, the potential of biogenic zinc oxide nanoparticles (ZnO NPs) in the removal of alizarin yellow R (AY) from aqueous solutions by photocatalytic degradation, as well as adsorption, was investigated. The synthesized ZnO NPs were prepared by the simple wet-combustion method using the plant extract of Serratula coronata L. as a reducing and stabilizing agent and characterized by powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray and X-ray photoelectron spectroscopy. Photocatalytic degradation of AY was monitored by UV–visible spectroscopy and the effects of parameters, such as light source type (UV-, visible- and sunlight), incubation time, pH, catalyst dosage and temperature on degradation were investigated. It was demonstrated that the source of light plays an important role in the efficiency of the reaction and the UV-assisted degradation of AY was the most effective, compared to the others. The degradation reaction of AY was found to follow the Langmuir-Hinshelwood mechanism and a pseudo-first-order kinetic model. The degradation kinetics of AY accelerated with increasing temperature, and the lowest activation energy (Ea) was calculated as 3.4 kJ/mol for the UV-light irradiation system, while the Ea values were 4.18 and 7.37 kJ/mol for visible light and sunlight, respectively. The dye removal by the adsorption process was also affected by several parameters, such as pH, sorbent amount and contact time. The data obtained in the kinetics study fit the pseudo-second-order equation best model and the rate constant was calculated as 0.001 g/mg·min. The isotherm analysis indicated that the equilibrium data fit well with the Freundlich isotherm model. The maximum adsorption capacity of AY on biogenic ZnO NPs was 5.34 mg/g. [ABSTRACT FROM AUTHOR]

In this study, reduced graphene oxide (RGO) was first synthesized and then it was reacted by alizarin red S (ARS), and therefore RGO functionalized with ARS was prepared (ARS/RGO). Then, structural analysis of the manufactured material was done by SEM and FTIR techniques. The FTIR results confirmed the interaction between ARS and RGO and the formation of ARS/RGO. A new electrochemical sensor was fabricated on the surface of a glassy carbon electrode modified with ARS/RGO. The prepared electrode showed a quasi-reversible electrochemical behavior and also had a significant effect on the electrocatalytic oxidation of caffeine (CAF). The modified electrode was able to measure the CAF as an electrochemical sensor. The effect of different parameters was investigated on the oxidation of CAF at the modified electrode; the sensor has the highest current at pH = 4.0. The effect of different interference species on the response of CAF, and also the reproducibility and repeatability of the sensor was investigated and acceptable results were obtained. The electrochemical determination of CAF on the electrode surface was investigated by differential pulse voltammetry and in the linear range of 1.0-100.0 µM, the detection limit value was obtained as 0.022 µM. Finally, the designed sensor was used to measure the amount of CAF in some real samples and satisfactory results were obtained. [ABSTRACT FROM AUTHOR]

Fish marking is an essential tool for fisheries management, especially for evaluating the stocking of endangered fish species to support conservation and sustainable use of fish stocks. Batch marking of young European eels Anguilla anguilla (L.) prior to stocking is recommended as the benefits of stocking for the spawning stock can be evaluated by recapturing marked fish over time, therefore mass marking of young eels with substances such as alizarin red S (ARS) is becoming increasingly important. To improve the marking method and reduce marking costs when immersing glass eels in an ARS solution, eight laboratory experiments under varying conditions (e.g., temperature, ARS concentration, immersion time, osmotic induction, fish density) and with ARS from different suppliers were carried out. The results show that optimal marking of glass eels can be carried out in the field or during transport by putting approximately 50 g of glass eels per liter in 150 mg L -1 ARS solution for 3 h at 10-15°C. Lower concentrations did not result in reliable marking. Water temperatures of 5°C and below can have a stunning effect on the eels and increase mortality significantly, regardless of the concentration of ARS. Glass eel densities below 50 g L -1 in the marking bath increase marking costs unnecessarily, while a higher density of 100 g L -1 resulted in significantly higher mortality and lower marking success. A somewhat more difficult but less expensive alternative is to bathe the fish in a saline solution of 1% (10 PSU) of 80 mg L -1 ARS for 3 h at 10°C. Costs can also be significantly reduced by choice of supplier for ARS, but care should be taken as the quality of the powder appears to vary (mean percentage of sufficiently marked eels ranged from 59% to 91% among suppliers in the present study) and can lead to marking failure. The optimal marking conditions can help ensure that stocked glass eels can be reliably identified in future studies to assess stocking benefits while reducing costs., (© 2024 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles.)

Carbon dot-based nanomaterials show great potential for environmental pollution control and remediation applications. Herein, carbon dots/silica nanoaggregates for dye adsorption were easily synthesized via a hydrothermal reaction of N-doped carbon dots with (3-aminopropyl)triethoxysilane. The composition and structure of the resulting nanoaggregates were characterized using TEM, SEM, FT-IR and XPS. The adsorbent exhibited ultrahigh adsorption capability for alizarin red S (1327 mg g−1) and malachite green (4091 mg g−1), outperforming most of the reported adsorbents. The effects of pH, adsorbent dosage, contact time and initial dye concentration on adsorption capacities have been investigated. The adsorption isotherms and kinetics were well fitted using the Langmuir and pseudo-second order models, indicating that monolayer adsorption and chemisorption of dye molecules occurred on the surface of carbon dots/silica nanoaggregates. The fabrication of carbon dots/silica nanoaggregates is simple, low-cost and eco-friendly, and it is easy to separate the material from water for recycling in practical applications. To the best of our knowledge, this is the first investigation into the application of carbon dots/silica nanoaggregates for the adsorption of organic dyes, which facilitates the development of carbon dot-based nanomaterials for environmental applications. [ABSTRACT FROM AUTHOR]

Copper oxide nanoparticles are prepared adopting green synthesis route by using Aloe vera plant extract instead of synthetic and polymeric stabilizing agents in mild alkaline aqueous conditions. The synthesised CuO nanoparticles (CuO nps) are characterised by Powder XRD and HR-TEM measurements. Using the as –synthesized CuO nps and reduced graphene oxide (rGO), nanocomposites comprising CuO nps- rGO are prepared by hydrothermal and ultrasonic methods. Nano composites are characterized using Powder XRD, HR-TEM and FE-SEM data. The fabricated CuO nps - rGO nanocomposites are coated onto glassy carbon electrode (GCE) for facile detection and electro oxidation of water polluting dyes such as the Ponceau 4R (P4R) and Alizarin Red (AR) using cyclic voltammetry . Electro oxidation of the dyes occurred at appreciably lower oxidation potentials like 0.45 V and 0.6 V for P4R and AR respectively along with the decoloration of the dyes. The absorbance of the analyte dye solutions are measured at intervals of time of progress of electro oxidations. The overall first order rate coefficient values for dye degradations are found out from absorbance time variance data. The results indicate that CuO nps - rGO nanocomposites decorated GCE acted as an efficient electrode surface for sensing and degradation applications for the chosen dye solutions. P4R azo dye degradation response was found to be better than AR anthroquinon dyes.

Two techniques, including chemical immobilization of a combination of two indicators of Alizarin and Orange dyes and the epoxy activation of the agarose membrane, were used for the preparation of a new optic pH sensor. For this purpose, the mentioned dyes were immobilized on agarose support activated by an epoxy, followed by optimizing the impacts of the coupling pH, as well as the ratio and concentration of the two dyes. The sensor was set up in a flow cell and effectively employed for online pH calculations. The new optic pH sensor could be applied between 4.5 and 11pH values. The sensor could quickly respond to pH alterations in nearly 25 s. The sensor's response is adjustable and replicable. Ionic strengths of up to 0.5 mol L−1 could have no meaningful impact on the response signal. In addition, no proof of any signal drift or dye leaching was detected over a three-month period. • The chemical immobilization of two indicators on agarose membranes activated by an epoxy could lead to a sensitive optic pH sensor for a wide range of pH. • The intended sensor was mounted in a flow cell and effectively utilized for the purpose of online pH measurement. • The suggested optode was employed to determine pH in real samples of water.

Food prone to spoilage has a huge food safety hazard, threatening people's health, so early detection of food spoilage is a continuous and urgent need. Herein, we developed a dual-mode response sensor, alizarin complexone@UiO-66-NH 2 , which can accurately detect pH. The sensor demonstrated significant changes in color from pale yellow to deep pink, while the fluorescence shifted from light blue to blue violet. Moreover, both UV absorption and fluorescence intensity showed a linear correlation with pH raging from 4.5 to 7.5. These results indicate that the sensor effectively responds to pH, making it suitable for detecting the freshness of perishable food. To put this into practice, we integrated the sensor with cellulose-based filter paper to determine the freshness of shrimp and beef, which was proved to be effective in assessing freshness. In the future, it can be combined with intelligent colorimetric and fluorescence instruments to achieve visual detection., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

A water‐soluble anthraquinone derived from alizarin, 3HAAQ, is introduced as the redox‐active material in a negative potential electrolyte (anolyte) for aqueous redox flow batteries operating at pH 14. The synthesis of 3HAAQ is carried out using the Mannich reaction, which significantly improves the solubility of the new compound, an important factor for its use in RFB. Pairing with potassium ferri/ferrocyanide positive electrolyte, this flow battery exhibits an open‐circuit voltage of 1.24 V and maintains nearly 80% of the theoretical capacity at 40 mA cm−2 current density. [ABSTRACT FROM AUTHOR]

In this paper, alizarin yellow GG (AYGG) – CuCl2 doped with polyvinyl alcohol (PVA) has been successfully synthesized. This composite has spherical shape particles with amorphous structure. Thermal analysis indicates that there is an endothermic change, which is related to the glass transition. In addition, the coordination between the transition metal Cu(II) ion and AYGG (ligand) occurs via oxygen atoms of phenolic hydroxyl groups and a nitrogen atom of azo moiety from the two ligand molecules. AYGG – Cu(II) doped PVA has high dispersion for high frequency lights and vice versa for low frequency lights. Therefore, it is concluded that AYGG – Cu(II) doped PVA film is suggested as a selective filter for ultraviolet and high frequency visible lights for many optical applications like protective shields for solar cells and packaging.

The use of color dyes in modern society presents a great challenge to the environment. Thus, extensive studies have been conducted in the last 30 years on the removal of color dyes from aqueous solutions such industrial wastewater. In this study, the removal of alizarin red S (ARS), an anionic dye, from solution by raw calcite (Cal) and heat-treated calcite (HCal) was conducted and compared under different physico-chemical conditions. Based on the isotherm study, the ARS removal capacities increased from 167 to 251 mmol/kg after the Cal was heated to 1000 °C for 3 h. The X-ray diffraction analyses showed no difference in the calcite phase between Cal and HCal after ARS sorption. Fourier-transform infrared results also showed no change in the calcite phase after ARS sorption, except a slightly increase in wavenumber from 713 to 727 cm−1 for the OCO bending of HCal at high ARS sorption levels. SEM observations showed about the same particle size and morphology before and after ARS sorption. The TGA data showed the formation of CaO after Cal was heated, and CaO converted back into calcite after being in contact with water or ARS solution for 24 h and then being air-dried. Thus, the high ARS removal could be due to CaO produced after Cal being heated. The findings from this research proved that there is great potential in the use of calcite, a low-cost and readily available Earth material, after heat treatment for the removal of contaminants from water. [ABSTRACT FROM AUTHOR]

Acne vulgaris is a common chronic inflammatory skin disease involving Cutibacterium acnes with other skin commensals such as Staphylococcus aureus and Candida albicans in the anaerobic and lipid-rich conditions of pilosebaceous units. These microbes readily form multispecies biofilms that are tolerant of traditional antibiotics as well as host immune systems. The phytopigment alizarin was previously found to prevent biofilm formation by S. aureus and C. albicans strains under aerobic conditions. Hence, we hypothesized that alizarin might control C. acnes and multispecies biofilm development. We found that under anaerobic conditions, alizarin efficiently inhibited single biofilm formation and multispecies biofilm development by C. acnes, S. aureus, and C. albicans without inhibiting planktonic cell growth. Alizarin increased the hydrophilicities of S. aureus and C. albicans cells, decreased lipase production by S. aureus, diminished agglutination by C. acnes, and inhibited the aggregation of C. albicans cells. Furthermore, the co-administration of alizarin and antibiotics enhanced the antibiofilm efficacies of alizarin against C. acnes. A transcriptomic study showed that alizarin repressed the transcriptions of various biofilm-related genes such as lipase, hyaluronate lyase, adhesin/invasion-related, and virulence-related genes of C. acnes. Furthermore, alizarin at 100 µg/mL prevented C. acnes biofilm development on porcine skin. Our results show that alizarin inhibits multispecies biofilm development by acne-causing microbes and suggest it might be a useful agent for treating or preventing C. acnes-causing skin diseases. [ABSTRACT FROM AUTHOR]

The effectiveness of chemical compounds for marking hard tissues in juvenile silver carp (Hypophthalmichthys molitrix) is not well known. We analyzed the use of alizarin complexone (ALC) as a fluorescent marker to mark the various hard structures of juvenile silver carp. Experimental fish (~2 months old) were randomly assigned to either control or marking groups, which were immersed in 0 or 100 mg/L ALC solutions, respectively, for 2 days. The otoliths, fin rays, and scales of the fish were then sampled, visualized using fluorescence microscopy, and evaluated after 10 days. The ALC treatment was effective for marking certain hard structures and the marking color was affected by the light source. There were no obvious differences in the marking efficiency of rays from pectoral, dorsal, ventral, anal, and caudal fins, but the lapilli and lateral line scales were marked most effectively from the sampled otolith and scale types, respectively. Our findings indicate that ALC immersion and fin ray and scale sampling can be used for the effective marking and non-lethal evaluation of hard structures in juvenile silver carp. [ABSTRACT FROM AUTHOR]

Automated methods exist for double staining bone and cartilage in fetal rat, rabbit and mice using alizarin red S and Alcian blue. None of the published methods produce consistently stained bone and cartilage in mouse fetuses. Consequently, we modified an automated staining method for use with mouse fetuses. Methanol replaced 95% industrial denatured alcohol, and 5% glacial acetic acid was used instead of 20%. We describe here our new protocol, which has been used successfully to stain specimens for regulatory prenatal developmental toxicity studies. [ABSTRACT FROM AUTHOR]

Adsorption of Alizarin Red S (ARS) on graphene oxide/poly(amidoamine) (GO/PAMAM) was studied at different ARS initial concentrations, temperatures, pHs, shaking rates and contact times. Adsorption sites of GO/PAMAM were phenolic –OHgroup of GO and amine groups (–NH2, –NH3+ and –NHR2+) of PAMAM dendrimer moieties of GO/PAMAM. At pH = 2 and 318 K, maximum adsorption capacity of the adsorbent was 1275.2 mg g–1 which is one of the highest capacity in the literature. Thus, GO/PAMAM in this work acted as a superadsorbent for ARS. At the incipient of adsorption, molecules were adsorbed on sites that was reaction-controlled step, (Ea = 114.5 kJ mol–1). Adsorption of on the remaining sites was diffusion–controlled. In alkaline media, two other types of ARS molecules were identified during that were adsorbed on and sites. Further increasing the pH of the solution, decreased the number these two sites and yielded a reduced adsorption capacity . Methylene blue (MB), thionine (Th), pyronin Y (PY), acridine orange (AO), methyl blue (MEB) and janus green (JG) dyes were selectively separated from their mixtures with ARS molecules using GO/PAMAM at pH of 2. The used adsorbent was recycled efficiently by using ethylenediamine very fast.

Fungi were used as one of the most common bioremediation methods. From this perspective, our study highlights the optimization of Alizarin Red S (ARS) dye adsorption performance for the sodium alginate (SA) by using the fungus Aspergillus terreus (A. terreus) to form a composite bead and the possibility of its reusability. This was accomplished by mixing SA with different ratios of biomass powder of A. terreus, including 0%, 10%, 20%, 30%, and 40%, to form composite beads of A. terreus/SA-0%, A. terreus/SA-10%, A. terreus/SA-20%, A. terreus/SA-30%, and A. terreus/SA-40%, respectively. The ARS adsorption characteristics of these composite mixtures were analyzed at various mass ratios, temperatures, pH values, and initial concentrations. Moreover, sophisticated techniques, such as scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR), were employed to detect the morphological and chemical properties of this composite, respectively. The experimental results revealed that A. terreus/SA-20% composite beads have the highest adsorption capacity of 188 mg/g. Its optimum adsorption conditions were achieved at 45 ∘C and pH 3. Moreover, the ARS adsorption was well explained by the Langmuir isotherm (qm = 192.30 mg/g) and pseudo-second-order and intra-particle diffusion kinetics. The SEM and FTIR findings corroborated the superior uptake of A. terreus/SA-20% composite beads. Lastly, the A. terreus/SA-20% composite beads can be employed as an eco-friendly and sustainable alternative to other common adsorbents for ARS.