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Along with a wide range of applications, the surface-enhanced Raman spectroscopy (SERS) is a prominent analytical technique to recognize and detect molecules and materials even at an extremely low molar concentration. In this work, a unique hybrid SERS platform is demonstrated by the incorporation of molybdenum disulfate (MoS2) nanoparticles (NPs) onto the core-shell AuPt hybrid NPs (HNPs) for the enhanced molecular Raman vibration of crystal violet (CV). The hybrid platform takes the advantage of both the electromagnetic mechanism (EM) offered by the AuPt HNPs and chemical mechanism (CM) owing to the MoS2 NPs. The distinctive core-shell morphology of AuPt HNPs with the high-density background Au NPs is attained by a unique two-step solid-state dewetting method, which can offer a high concentration of electromagnetic hot spots. At the same time, the MoS2 NPs can provide an ample charge transfer with abundant active sites. Through the hybrid SERS approach, a dramatic SERS enhancement of CV Raman vibration is demonstrated, and the SERS capability is thoroughly studied. In addition, the finite-difference time-domain (FDTD) simulations provide a deeper understanding of the electromagnetic field distributions for various configurations of nanostructures and their hybrid combinations: i.e., HNPs, alloy NPs, MoS2/HNPs configurations.

Novel hybrid aerogels, which can be magnetically extracted from water to avoid filtration, were prepared by adding ZnCl2, NiCl2·6H2O, FeCl2·4H2O and FeCl3·6H2O into a suspension of graphene oxide and oxidzed carbon nanotubes followed by co-precipatation under basic condition, crosslinking with polyvinyl alcohol in water and freeze-drying. The hybrid aerogels consist of magnetic Ni0.5Zn0.5Fe2O4 nanoparticles, graphene oxide, carbon nanotubes and polyvinyl alcohol, which have active sites that attract dye molecules and can be extracted from water by applying magnetic field. Under an optimal mass ratio of the components, the optimized hybrid aerogel has a high adsorption capacity (qe=71.03 mg g−1 for methylene blue) and a moderate magnetic strength of MS = 3.519 emu g−1. Its removal efficiencies for methylene blue, methyl orange, crystal violet and their mixture with an equal mass are 70.1%, 4.2%, 8.9% and 11.1%, respectively under the same dye concentration of 0.025 mg. mL−1. It can be reused for 3 regeneration cycles with a regeneration efficiency of over 82%. Also it is not toxic to the living organism, suggesting that it is promising as an adsorbent for treating industrial wastewater.

Introduction Strains can be classified in terms of biofilm production from quantitative absorbance values collectively by dividing strains into tertile ranks or individually by calculating the optical density for the negative control. However, these methods have not been compared in a large sample of Staphylococcus aureus strains. Therefore, our objective was to analyze the agreement between both methods in terms of biomass production and metabolic activity of their biofilm. Methods We classified 233 S. aureus strains by biomass production and metabolic activity using the crystal violet and XTT assays, respectively. Strains were classified as low, moderate, or high biofilm producers according to tertile or optical density. Results We found no agreement between both methods (p Conclusions We consider strains’ biofilm classification by optical density to be a more reliable method, as it depends on the individual absorbance of each strain.

Textile wastewater contains highly toxic, nondegradable, carcinogenic organic pollutants, causing severe damage to the ecological environment. In this work, β-cyclodextrin carbon-sphere-based nanocomposite (CS/SiO2@β-CD) with a core–shell–shell configuration was prepared by hydrothermal synthesis and subsequent sedimentation-azeotropic distillation with SiO2 as intermediate layer for the removal of crystal violet (CV) and bisphenol A (BPA). The chemical structure and morphology of the CS/SiO2@β-CD were characterized by FT-IR, SEM and TEM. The effects of contact time, pH, temperature and initial concentration of the absorbates on the adsorption property were explored. The CS/SiO2@β-CD showed excellent adsorption capacity on CV and BPA, and the maximum adsorption capacity was 87.873 mg g–1 and 165.095 mg g–1, respectively. Their adsorption process was in line with the pseudo-second-order and pseudo-first-order kinetic models, respectively. The adsorption thermodynamics could be better fitted by Langmuir model than by Freundlich model. The calculated thermodynamic parameters (–ΔG0, ΔS0 and ΔH0) illustrated the adsorption of CV was endothermic, in contrast, the adsorption of BPA was exothermic process. Furthermore, the CS/SiO2@β-CD showed excellent recovery performance, making it a potential adsorbent for the practical treatment of textile wastewater.

Aims Because the Staphylococcus aureus is one of the most well-known pathogens associated with medical devices and nosocomial infections, the aim of the study was to examine antibiofilm potential of emodin against it. Methods and Results Antibacterial activity was examined through microdilution assay. Antibiofilm testing included crystal violet staining of biofilm biomass and morphology analysis by Atomic force microscopy (AFM). Furthermore, aerobic respiration was monitored using the Micro-Oxymax respirometer. For investigation of gene expression qRT-PCR was performed. Emodin demonstrated strong antibacterial activity and ability to inhibit biofilm formation of all tested strains. The effect on preformed biofilms was spotted in few strains. AFM revealed that emodin affects biofilm structure and roughness. Monitoring of respiration under emodin treatment in planktonic and biofilm form revealed that emodin influenced aerobic respiration. Moreover, qRT-PCR showed that emodin modulates expression of icaA, icaD, srrA and srrB genes, as well as RNAIII, and that this activity was strain-specific. Conclusion The results obtained in this study indicate the novel antibiofilm activity of emodin and its multiple pathways of action. Significance and Impact of Study This is the first study that examined pathways through which emodin expressed its antibiofilm activity.

The aim of this study was to determine whether the antibacterial activity of chitosan-modified Fe3O4 (CS@Fe3O4) nanomaterials against Acinetobacter baumannii (A. baumannii) is mediated through changes in biofilm formation and reactive oxygen species (ROS) production. The broth dilution method was used to examine the effect of CS@Fe3O4 nanoparticles on bacterial growth. The effects of CS@Fe3O4 nanoparticles on biofilm formation were measured using a semi-quantitative crystal violet staining assay. A bacterial ROS detection kit was used to detect the production of ROS in bacteria. CS@Fe3O4 nanoparticles had a significant inhibitory effect on the colony growth and biofilm formation of drug-resistant A. baumannii (p < 0.05). The ROS stress assay revealed significantly higher ROS levels in A. baumannii subjected to CS@Fe3O4 nanoparticle treatment than the control group (p < 0.05). Thus, we demonstrated for the first time that CS@Fe3O4 nanoparticles had an inhibitory effect on A. baumannii in vitro, and that the antibacterial effect of CS@Fe3O4 nanoparticles on drug-resistant A. baumannii was more significant than on drug-sensitive bacteria. Our findings suggest that the antibacterial mechanism of CS@Fe3O4 nanoparticles is mediated through inhibition of biofilm formation in drug-resistant bacteria, as well as stimulation of A. baumannii to produce ROS. In summary, our data indicate that CS@Fe3O4 nanoparticles could be used to treat infections caused by drug-resistant A. baumannii.

As a newly emerging pathogen, Candida auris has spread rapidly and caused a serious invasive infection. Candida auris often appeared high resistance to classical antifungal drugs. Drug combination therapy is emerging as an effective and well-established strategy to relieve drug resistance problems. The objective of present work was to examine the activity of fluconazole in combination with chlorhexidine acetate against Candida auris isolates.Antiplanktonic activity was studied using the EUCAST methodology and growth curve assay. Antibiofilm effectiveness was determined by the crystal violet method, checkerboard microdilution assay, scanning electron microscopy, and confocal laser scanning microscopy.The results indicated that the 80% minimal inhibitory concentrations for fluconazole alone against Candida auris were 2-32 mg/L and for chlorhexidine acetate were 2-8 mg/L. The combination of fluconazole with chlorhexidine acetate exhibited synergism with the growth curve assay. In addition, the checkerboard microdilution assay presented that fluconazole was strongly synergistic with chlorhexidine acetate (sFICI0.1875) in inhibiting the growth of Candida auris biofilms. The scanning electron microscopy and confocal laser scanning microscopy further exhibited the alteration of morphology of the cells and architecture of the biofilms.The combination therapy of fluconazole and chlorhexidine acetate provides a new potential strategy for the treatment of clinical Candida auris infection.

Continuous release of synthetic dyes from industrial effluent into surface water poses a huge environmental threat and health hazard to humans and aquatic life. The need to right the wrong occasioned by the inimical industrial practice of uncontrolled release of carcinogenic dyes into the surface water calls for research into effective treatment technologies for the treatment of dye-contaminated industrial effluent. The isotherm of Crystal Violet (CV) solution on activated carbon (AC) synthesized from millet stover was investigated and presented herein. Samples of AC were synthesized from millet stover at 120⁰C using phosphoric acid as the activating agent. Employing varying mix ratios of stover-to-phosphoric acid (1:0, 1:1, 1:2, 1:3, and 1:4), respective samples of AC were synthesized. The batch adsorption process of the various samples of the AC in 15 mg/l initial concentration of an aqueous solution of CV was carried out at varying times. The CV’s change in the sorbate’s concentration was monitored using a UV spectrophotometer. The optimum adsorption time was 240 min. The optimally synthesized activated carbon was the 1:2 sample having an equilibrium sorbent concentration of 0.74 mg/L and sorbate uptake of 95.1%. Langmuir, Freundlich and Temkin isotherm models were employed for the isotherm analysis. The values of the Langmuir, Freundlich and Temkin models were 0.99, 0.90, and 0.94, respectively. The isotherm constants for the Langmuir, Freundlich and Temkin models were –1.52 l/mg, –4.08, and 0.005 l/min, respectively. The Langmuir isotherm model best fitted the adsorption mechanism with a maximum equilibrium adsorption capacity of 14.0 mg/g.

Existence of a very lesser quantity of dyes in water, which are still highly visible, extremely affects the quality and clearness of water bodies such as lakes, rivers, ponds and others water bodies, leading to harm to the aquatic environment. So it is significant to eliminate the harmful dyes which are very hazardous to the living organisms. Treatment of wastewater is challenging because dyes are water soluble so its removal becomes tough. In this work synthetic copolymer adsorbent of AA and AMP was successfully synthesized at many compositions. All the characteristic absorption bands of PAA and PAMP are observed by FTIR analysis, which indicates the successful copolymerization of AA and AMP. Adsorption experiments were accomplished at different contact time, adsorbent dose, pH conditions and temperature. 0.1 g dose of copolymer adsorbent has been found to be optimum for adsorption study. The kinetic study of adsorption was also investigated using pseudo first order kinetic model. From the study, it was establish that the prepared copolymer adsorbent was proficient to eliminate crystal violet dye at various temperature and time. Maximum 98% of crystal violet dye removal was achieved at high pH around 10. A maximum adsorption capacity of 9.8 mg/g was obtained for copolymer adsorbent of 1:1 ratio. Copolymer adsorbent (AA-AMP) provide a novel and effective type of adsorbents to remove CV dye from the aqueous solution.

Staphylococcus auerus (S. aureus) biofilms are a frequently associated cause of artificial implant infections and failures. Surface coating of titanium (Ti), a widely used implant biomaterial with antimicrobial agents may appear a promising approach to prevent and reduce the periimplant infections and associated failures. Natural antimicrobial peptides (AMPs) viz laterosporulins (LS) from soil bacteria Brevibacillus spp. were bound on titanium (Ti) substrates using a simple, time and cost effective chemical processing technique. Resistance of the AMP coated Ti substrates against biofilm formation of the bacterium S. aureus was determined by crystal violet staining, in vitro. Further the antibiofilm activity was visualized in replicate experiments on Hydroxyapatite (HA) discs also to simulate enamel surfaces consistently layered by saliva in oral cavity to ascertain the biofilm inhibition assessment. AMP coated Ti substrates showed marked reduction in the biofilm formation by S. aureus, in vitro compared against the control-Ti surfaces. Further, Coated HA discs also substantiated the findings in a similar trend compared with control-Ti substrates. The findings suggested a promising potential for laterosporulins as effective antibiofilm agents for coating titanium surfaces for various applications, including dental implants used in oral cavity.

This study aimed to determine the extractive yield, the spilanthol content and the bactericide and antibiofilm activities of aqueous and hydroethanolic extracts of two regional variations (Amapa and Para) of Acmella oleracea (L.) R. K. Jansen against the cariogenic bacteria Streptococcus mutans. Aqueous extracts of leaves and hydroethanolic extracts of leaves and stems were obtained and submitted to UHPLC-ESI-QToF-MS/MS characterization. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extracts were determined using the microdilution method, while the crystal violet assay was used to access the activity over S. mutans pre-formed 1-day biofilms. The aqueous extracts of the leaves showed higher extractive yields compared to the hydroethanolic solutions. Nonetheless, the hydroethanolic mixture ensured a higher extraction of spilanthol. For instance, the leaves of Para variation (EELAO-PA) (99.97%) and the stem of Amapa variation (EESAO-AP) (99.17%) presented the highest spilanthol content. Therefore, these extracts were selected for the antimicrobial assays, presenting equally MIC and MBC of 125 µg/ml against S. mutans. In the antibiofilm assay, EELAO-PA at 500 µg/ml (4xMIC) presented an inhibition of 50.89% after a 1-minute single application, similarly (p>0.05) to that found after chlorhexidine gluconate 0.12% treatment. Accordingly, A. oleracea rich spilanthol extracts showed remarkable antibacterial activity against the cariogenic S. mutans and could become an affordable coadjuvant used in dental products to prevent and control dental caries.

Herein, a low-cost and green adsorbent (Pect/AILP-Kal) was successfully synthesized from pectin modified with hybrid mixture of Azadirachta indica leaves and kaolin clay and further analyzed as an efficient adsorbent for sequestration of MB and CV dyes. Effect of the operational parameters, for instance concentration, temperature, dose, pH and contact time on adsorption characteristics were studied in detail. The optimum pH for sequestration of MB and CV was obtained at pH 7.5 with time of 180 min. Adsorption kinetics for MB and CV dyes was best followed with pseudo-second order. The equilibrium data showed that the Langmuir was best obeyed with an isotherm model. The endothermic and spontaneous nature was indicated by the positive ΔH° values and negative values of ΔG° calculated from the thermodynamic parameters. Breakthrough and exhaustive capacities were identified as being 16 and 76 (mg g−1) for MB while 20 and 72 (mg g−1) for CV dyes respectively. Desorption results showed that synthesized (Pect/AILP-Kal) nanocomposite can be reused upto fifth cycle successfully. In order to remove these hazardous dyes from aqueous solution, (Pect/AILP-Kal) nanocomposite can be utilized very effectively and economically.

This study evaluates the production of hydrochars from the outer shells of the nut group (peanut, hazelnut, walnut, and pistachio) in an eco-friendly subcritical water medium (SWM) and their effects as adsorbents on the removal of crystal violet (CV) from an aqueous solution. The prepared hydrochars were characterized using Brunauer Emmett-Teller (BET) analysis, scanning electron microscope (SEM), Fourier transforms infrared spectroscopy (FTIR), and zeta potential. The adsorption process was optimized based on pH, adsorbent dose, dye concentration, and contact time. The hazelnut hydrochar was found to have the maximum removal efficiency (91%). Optimum conditions were pH of 8, particle size

Background The widespread application of polymeric membranes in water filtration has raised concerns on the disposal of the large amount of resultant solid waste. The aim of this research was the preparation of a new environmentally-friendly membrane using polycaprolactone (PCL) biodegradable polymer and its modification through the addition of hydrophilic MXene nanosheets (Ti3C2(OH)2). Methods In this study, the nanosheets were synthesized and then characterized to confirm their layered structure and the presence of the hydroxyl group in them. The pure and also the modified PCL membranes were characterized thoroughly. Biodegradability of membranes was also evaluated through burial in compost. Significant findings The results showed that the PCL membrane incorporated with 4 wt. % MXene exhibited the highest hydrophilicity. Also, all the nanocomposite membranes showed improved tensile properties and biodegradability. Filtration results implied that the membrane loaded with 4 wt. % MXene had the highest pure water permeance (PWP), which was almost 4 times as much as the pure PCL membrane (5.99 vs 1.43 L/m2.h.bar, respectively). Moreover, the membrane incorporated with 1 wt. % MXene provided 98.92% rejection of crystal violet (Mw of 407.98 g/mol, dye concentration in the feed solution: 50 ppm), which was only slightly lower than that of the neat PCL membrane (i.e., 99.38%).

In recent years, lithium-containing ceramic materials have attracted considerable research attention as high-temperature adsorbents of carbon dioxide. The recycling of electrode materials from spent lithium-ion batteries for use as photocatalysts in recovering CO2 and degrading organic pollutants is worthy of exploration. Solid, magnetic ferrite-containing photocatalysts are easily separated from reaction solutions by using magnetic devices. Solid catalysts (e.g., LiFeO2, LiFe5O8, NaFeO2, and K2Fe2O4) were prepared through the calcination of Fe2O3 and M2CO3. CO2 was photoreduced and crystal violet (CV) and 2-hydroxybenzoic acid (2-HBA) were photodegraded under visible light irradiation. The optimized K2Fe2O4 photocatalyst increased the rate of photocatalytic conversion from CO2 to methane at 20.9 µmol g−1 h−1. The catalytic efficiency indicated that the optimized reaction rate constants of CV with LiFeO2, NaFeO2, and K2Fe2O4 were 2.98 × 10−1, 5.32 × 10−1, and 4.36 × 10−1 h−1, respectively. The quenching effect achieved through the use of various scavengers and the electron paramagnetic resonance in CV degradation revealed the substantial contribution of the reactive superoxide anion radical O2 − and the minor roles of h+ and the OH radical. Its usefulness in the synthesis of solid-base catalyst MFeO2 is promising for environmental control and relevant applications, particularly in solar energy manufacturing.

Mengying Mao,1– 3 Wenjie Zhang,2– 4 Zhengwei Huang,1– 3 Jing Huang,1– 3 Jia Wang,1– 3 Weiping Li,1– 3 Shensheng Gu1– 3 1Department of Endodontics, Shanghai Ninth People’s Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China; 2National Clinical Research Center for Oral Diseases, Shanghai, People’s Republic of China; 3Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, People’s Republic of China; 4Department of Prosthodontics, Oral Bioengineering and Regenerative Medicine Lab, Shanghai Ninth People’s Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of ChinaCorrespondence: Shensheng GuDepartment of Endodontics, Shanghai Ninth People’s Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, 639 Zhizaoju Road, Shanghai, 200011, People’s Republic of ChinaEmail gss2m9h@163.comWeiping LiShanghai Ninth People’s Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, 639 Zhizaoju Road, Shanghai, 200011, People’s Republic of ChinaEmail wp_li95814@163.comIntroduction: Dental caries is a biofilm-dependent disease that largely relies on the ability of Streptococcus mutans to synthesize exopolysaccharide matrix. Graphene oxide-based metal nanomaterials, as the derivatives of graphene, are potent agents against pathogens by their impressive antibacterial and anti-biofilm biofunctions. Previously, we fabricated the novel graphene oxide-copper nanocomposites (GO-Cu), maintaining a long-term release of copper nanoparticles. Here, the biofunctionalization of GO-Cu nanocomposites against cariogenic S. mutans is investigated.Methods: Growth curve observation and colony forming units counting were applied to detect the antibacterial effect of GO-Cu nanocomposites on S. mutans. Scanning electron microscopy and the crystal violet assay were used to detect nanocomposite effects on biofilm forming ability. The production and distribution of exopolysaccharides within biofilm was analyzed and the expression of genes required for biofilm formation was explored. Moreover, the regulatory landscape of GO-Cu nanocomposites on S. mutans pathogenicity was probed.Results: It has been found that GO-Gu nanocomposites were antibacterial to S. mutans and 10 μg/mL GO-Cu nanocomposites could inhibit the bacteria bioactivity instead of killing them. The biomass of S. mutans biofilm was significantly reduced when treated with 10 μg/mL GO-Cu nanocomposites. Also, 10 μg/mL GO-Cu nanocomposites could alter the biofilm architecture and impair exopolysaccharides production and distribution, and dysregulated the expression of exopolysaccharide-associated genes.Conclusion: In all, we found low-dose GO-Cu nanocomposites could disrupt exopolysaccharide matrix assembly and further impair optimal biofilm development with minimal cytotoxicity. Therefore, GO-Cu nanocomposites can open up a new avenue for the development of alternative anti-caries biomaterials.Keywords: graphene oxide-copper nanocomposites, anti-biofilm, Streptococcus mutans, exopolysaccharides, dental caries

A novel zwitterionic superabsorbent polymer hydrogel poly(MEMA-DMAPS) was synthesized using three different combinations of 2-(N-morpholino) ethyl methacrylate (MEMA) and 3-((2-methacryloyloxy)ethy...

In this study, Ficus religiosa leaves (FRLs) and Daucus carota pomace (DCP) were used effectively for the removal of carcinogenic and non-biodegradable Crystal Violet dye from the aqueous medium on the batch scale as low-cost and environment-friendly biosorbents. Certain experimental conditions such as adsorbent dose, contact time, pH, and temperature were studied for thermodynamic and isothermal data investigations and optimized conditions for F. religiosa leaves and D. carota pomace were: adsorbent dose; 0.8 and 1.8 g, contact time; 30 and 25 min, pH; 9 and 3 and temperature; 70 °C and 30 °C, respectively. Langmuir, Freundlich, Temkin, and D-R isotherms were studied, and the sorption process indicated chemisorption mode is predominant. The same is supported by kinetic investigation of equilibrium data. The maximum adsorption capacity (qmax) for F. religiosa leaves and D. carota pomace was obtained as 2.4 and 27 mg/g, respectively, which showed that D. carota pomace (DCP) is more effective adsorbent than F. religiosa leaves (FRLs) for removal of CV dye. Exothermic nature and intraparticle diffusion mode are more predominant during the removal of CV dye by these biomaterials, which can be recycled using ethanol.[Figure: see text]Novelty statement: Ficus religiosa and Daucus carota biowaste was explored here for removing an anionic dye. This study will be helpful for exploring the waste potential for phytoremediation of toxic substances using indigenous resources in an ecofriendly way.

Wastewater treatment is of great significance to environmental remediation. The exploration of efficient and stable methods for wastewater treatment is still a challenging issue. Herein, a heterojunction material with photocatalysis and adsorption properties has been designed to remove the complex pollutants from wastewater. The heterojunction material (ZnO/TiO2 -PW12 , PW12 =[PW12 O40 ]3- ) was synthesized by calcining the ZnTi-layered double hydroxide (ZnTi-LDH) intercalated with the Keggin-type polyoxometalate H3 PW12 O40 . In the construction of ZnO/TiO2 -PW12 it was found that the polyanionic PW12 remained unchanged in the process of forming the proposed heterojunction. The photochemical properties verify that heterojunction synergistic with PW12 facilitated the separation of photoproduced electron-hole pairs and thus suppressed the recombination. Therefore, ZnO/TiO2 -PW12 exhibits excellent photocatalytic property, and the efficiency of Cr(VI) photoreduction reached more than 90 % in the first 3 min. Furthermore, the electrostatic force between the PW12 and cationic dyes makes ZnO/TiO2 -PW12 having an outstanding adsorption performance for cationic dyes, such as rhodamine B, crystal violet and methyl blue. Such heterojunction material combined with polyoxometalate puts forward new insights for the design of functional materials for water treatment with low cost and high efficiency.

Microbial infections remain a public health problem due to the upsurge of bacterial resistance. In this study, the antibacterial, antibiofilm, and efflux pump inhibitory activities of the stem bark of Acacia macrostachya, an indigenous African medicinal plant, were investigated. In traditional medicine, the plant is used in the treatment of microbial infections and inflammatory conditions. A crude methanol extract obtained by Soxhlet extraction was partitioned by column chromatography to obtain the petroleum ether, ethyl acetate, and methanol fractions. Antibacterial, efflux pump inhibition and antibiofilm formation activities were assessed by the high-throughput spot culture growth inhibition (HT-SPOTi), ethidium bromide accumulation, and the crystal violet retention assay, respectively. The minimum inhibitory concentrations (MICs) of the crude extract and major fractions ranged from 250 to ≥500 μg/mL. At a concentration of 3.9–250 μg/mL, all extracts demonstrated >80% inhibition of biofilm formation in S. aureus. In P. aeruginosa, the EtOAc fraction showed the highest antibiofilm activity (59–69%) while the pet-ether fraction was most active against E. coli biofilms (45–67%). Among the test samples, the crude extract, methanol, and ethyl acetate fractions showed remarkable efflux pump inhibition in S. aureus, E. coli, and P. aeruginosa. At ½ MIC, the methanol fraction demonstrated significant accumulation of EtBr in E. coli having superior efflux inhibition over the standard EPIs: chlorpromazine and verapamil. Tannins, flavonoids, triterpenoids, phytosterols, coumarins, and saponins were identified in preliminary phytochemical studies. Stigmasterol was identified in the EtOAc fraction. This study justifies the use of A. macrostachya in the treatment of infections in traditional medicine and highlights its potential as a source of bioactive compounds that could possibly interact with some resistance mechanisms in bacteria to combat antimicrobial resistance.

In this work, novel mixtures based on silicon and tin materials were synthesised via reaction of 2.407, 5.247, 7.195, or 9.59 g of tin chloride dihydrate with 6 g of sodium metasilicate pentahydrate. The samples, which were synthesised using 2.407, 5.247, 7.195, and 9.59 g, are abbreviated as T1, T2, T3, and T4, respectively. XRD confirmed that these mixtures consist of amorphous Sn/Si, sodium tin silicate, tin oxide, and sodium silicate. The average crystallite size of T1, T2, T3, and T4 samples is 5.23, 8.13, 12.26, 15.72 nm, respectively. The synthesised mixtures were used as adsorbents for the removal of methylene blue and crystal violet dyes from aqueous media. 15 min, pH 6, and 298 Kelvin are regarded as the optimum conditions for the removal of studied dyes using T1, T2, T3, and T4 samples. The adsorption process of crystal violet or methylene blue dyes was fitted well with the Langmuir equilibrium isotherm and pseudo-second-order kinetic model. The thermodynamic parameters confirmed that the removal of crystal violet and methylene blue dyes is chemical, spontaneous, and exothermic. The maximum adsorption capacity of T1, T2, T3, and T4 samples towards crystal violet dye is 34.81, 36.83, 29.46, and 11.98 mg/g, respectively. Also, the maximum adsorption capacity of T1, T2, T3, and T4 samples towards methylene blue dye is 30.13, 29.33, 17.09, and 13.43 mg/g, respectively. HCl: butanol (1:3) can efficiently desorb the dyes for three cycles of adsorption/desorption. Hence, the adsorbents can be used successfully several times for the removal of crystal violet and methylene blue dyes.

The main objective of this study is to optimize a new composite for the depollution of contaminated water. The sodium hydroxide-modified avocado shells (NaOH-AS) were firstly prepared, characterized by field-emission-scanning-electron-microscopy (FE-SEM), X-ray energy dispersive spectroscopy (EDS) and Fourier transforms infrared (FT-IR) spectroscopy, and applied for efficient removal of crystal violet dye (CV) in wastewater. In addition, the adsorption in a batch system of CV dye on the NaOH-AS material was studied. Therefore, we accomplished a parametric study of the adsorption by studying the effect of several important parameters on the decolorizing power of the used material, namely, initial pH, contact time, initial CV dye concentration, temperature, and the ionic strength effect on the CV dye adsorption process were systematically assessed. The highest adsorption efficiency of CV dye (>96.9%) by NaOH-AS was obtained at pH >8. The pseudo-second-order kinetic model gave the best description of the adsorption kinetic of CV dye on the AS and NaOH-AS adsorbents. In addition, the mass transfer of CV dye molecules from the solution to the adsorbent surface occurred in three sequential stages (boundary layer diffusion, intraparticle diffusion and adsorption equilibrium). The adsorption isotherm data were best fitted with the Freundlich model. The adsorption capacity of AS increased from 135.88 to 179.80 mg g−1 after treatment by 1 M NaOH. The thermodynamic study showed that CV dye adsorption onto NaOH-AS was an exothermic and feasible process. The electrostatic interactions acted as the only forces governing the CV adsorption mechanism. The NaOH-AS demonstrated a satisfactory reusability. Therefore, we can state that the as-developed NaOH-AS material has a potential application prospect as an efficient adsorbent for CV dye from wastewaters. HIGHLIGHTS NaOH-AS is an efficient adsorbent for removal of crystal violet dye from aqueous solutions.; Equilibrium data were well described by Freundlich isotherm model.; The maximum uptake capacity was found to be 179.80 mg/g.

A novel arginine-modified Heliotrope leaf (Arg@HL) was used as adsorbent for the crystal violet (CV) dye adsorption in a batch process. The physicochemical and morphological composition of Arg@HL were characterized by field-emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The experiments were carried out to investigate the factors that influence the dye uptake by the adsorbent, such as the contact time under agitation, adsorbent amount, initial dye concentration, temperature and pH of dye solution. The optimum conditions of adsorption were found on the batch scale as followed: CV concentration of 20 mg·L−1, an amount of 0.75 g·L−1 of the adsorbent, 90 min contact time, 6 pH and 25 °C temperature for Arg@HL. The results confirmed a second-order model explaining the dye crystal violet's adsorption's kinetics by Arg-Heliotrope leaves. The Langmuir model effectively defines the adsorption isotherms. The results revealed that the Arg@HL has the potential to be used as a low-cost adsorbent for the removal of CV dye from aqueous solutions. HIGHLIGHTS The first effort to use a low-cost arginine-modified Heliotrope leaves material as an adsorbent for crystal dye elimination by adsorption procedures.; CV dye was efficiently removed using Arg@HL.; Arg@HL exhibited high adsorption capacity for CV dye.; Adsorption process follows the Langmuir isotherm.

A new magnetic nanocomposite clinoptilolite (CLT)/Starch/CoFe2O4 was synthesized using co-precipitation method. The prepared magnetic composite powder was utilized for decontamination of methylene blue dye (MBD), methyl violet dye (MVD), and crystal violet dye (CVD) from water media. The BET analysis showed that CLT modification using starch and CoFe2O4 nanoparticles improved its specific surface and the amount of specific surface area for CLT, CoFe2O4, and CLT/Starch/CoFe2O4 powder was reported to be 18.82 m2.g−1, 151.4 m2.g-1, and 104.75 m2.g−1, respectively. Experimental results showed that pH 9 had a vital role in the adsorption process of all three types. Langmuir and Redlich-Petersen isotherm models were well fitted with experimental data. Also, the maximum adsorption capacity of CVD, MBD, and MVD to the desired composite was determined as 32.84 mg.g−1, 31.81 mg.g−1, and 31.15 mg.g−1, respectively. In addition, the kinetic data of the removal process followed a pseudo-first order (PFO) kinetic model. Negative thermodynamic parameters were indicated that the process is spontaneous and exothermic. Finally, ad(de)sorption experiments' results showed that the synthesized nanocomposite adsorbent has an excellent ability to adsorb cationic dyes after several consecutive cycles.

The treatment of textile wastewater comprising many dyes as contaminants endures an essential task for environmental remediation. In addition, combating antifungal multidrug resistance (MDR) is an intimidating task, specifically owing to the limited options of alternative drugs with multitarget drug mechanisms. Incorporating natural polymeric biomaterials for drug delivery provides desirable properties for drug molecules, effectively eradicating MDR fungal growth. The current study fabricated the bipolymeric drug delivery system using chitosan-gum arabic-coated liposome 5ID nanoparticles (CS-GA-5ID-LP-NPs). This study focused on improving the solubility and sustained release profile of 5I-1H-indole (5ID). These NPs were characterized and tested mechanically as a dye adsorbent as well as their antifungal potencies against the plant pathogen, Botrytis cinerea. CS-GA-5ID-LP-NPs showed 71.23% congo red dye removal compared to crystal violet and phenol red from water and effectively had an antifungal effect on B. cinerea at 25 μg/mL MIC concentrations. The mechanism of the inhibition of B. cinereavia CS-GA-5ID-LP-NPs was attributed to stabilized microtubule polymerization in silico and in vitro. This study opens a new avenue for designing polymeric NPs as adsorbents and antifungal agents for environmental and agriculture remediation.

The current study is focused on fabrication of a ternary metal oxide nanocomposite (ZnO/CuO/Ag2O) as an efficient and superior photocatalyst by step-wise implanting of p-type CuO and Ag2O semiconductors onto an n-type semiconductor (ZnO) via a chemical method. The structural and textural characteristics of the manufactured samples were characterized by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy combined with electron dispersive spectroscopy (FESEM-EDS) and UV–visible spectroscopy. The photocatalytic performance of the fabricated ternary nanocomposite was tested against the photocatalytic degradation of crystal violet (CV) and rhodamine B (RhB) organic dyes under solar light irradiation. The ternary nanocomposite demonstrated about 99.05% and 97.38% degradation efficiency toward CV and RhB dyes under solar light irradiation in a time period of 105 min. The calculated rate constants (k, min−1) for degradation under solar light over the ZnO/CuO/Ag2O nanocomposite were 4.26 and 3.61 times higher than the k value obtained over ZnO nanoparticles for CV and RhB dyes, respectively. The main reactive species taking part in the photodegradation processes were •OH and •O2− over ZnO/CuO/Ag2O photocatalysts under solar light illumination. Furthermore, the recycle experiments confirmed good reusability and photo-stability of the ZnO/CuO/Ag2O ternary nanocomposite. HIGHLIGHTS Ternary metal oxide (TMO) nanocomposite (ZnO/CuO/Ag2O) was prepared by step-wise deposition of p-type CuO and Ag2O semiconductors onto an n-type ZnO semiconductor.; As-prepared TMO has displayed enhanced photocatalytic activities against the CV (97.38%) and RhB (99.05%) dyes compared with binary ZnO/CuO metal oxide and ZnO nanoparticles under the solar light irradiation.

Wastewater treatment is one of the most important concerns of the research studies in the field of environmental protection. The current study relates to the removal of Crystal violet dye from aqueous solutions through adsorption experiments onto natural cellulosic supports. Various waste materials that have in their composition lignocellulose are adsorbent supports with low costs for the removal of heavy metal ions and dyes from aqueous solutions. The use of chemically modified sawdust to obtain an inexpensive adsorbent for removing the Crystal violet dye (CV) from synthetic aqueous solutions has been presented in this research paper. The influence of some important parameters such as: initial dye concentration, adsorbent dose, contact time and temperature on adsorption efficiency for this dye removal have been studied. The Freundlich, Langmuir and Temkin mathematical models have been used to evaluate the data of Crystal violet adsorption from aqueous media using wood sawdust. The research study shows that beech wood sawdust (Fagus sylvatica), as an agricultural waste which is readily available and relatively inexpensive has the potential to be an applicable alternative adsorbent for Crystal violet dye removal from industrial effluents.

This study aims to investigate the antibacterial and anti-biofilm activities of YycG inhibitors H2-60 and H2-81 against Streptococcus agalactiae. A total of 118 nonduplicate S. agalactiae clinical isolates were collected, and the minimal inhibitory concentrations (MICs) of H2-60 and H2-81 were determined. H2-60 and H2-81 inhibit biofilm formation of S. agalactiae were detected by crystal violet staining, and against established biofilms of S. agalactiae were observed by confocal laser scanning microscope. Inhibitory effect of H2-60 and H2-81 on the phosphorylation activity of the HisKA domain of YycG' protein was measured. The MIC50/MIC90 was 3.13/6.25 μM for H2-60 and 6.25/12.5 μM for H2-81 against S. agalactiae, respectively. S. agalactiae planktonic cells can be decreased by H2-60 or H2-81 for more than 3 × log10 CFU ml-1 after 24 h treatment. Biofilm formation of 8 S. agalactiae strains (strong biofilm producers) was significantly reduced after treated with 1/4 × MIC of H2-60 or H2-81 for 24 h. H2-60 and H2-81 could reduce 45.79% and 29.56% of the adherent cells in the established biofilm of S. agalactiae after 72 h treatment, respectively. H2-60 combined with daptomycin reduced 83.63% of the adherent cells in the established biofilm of S. agalactiae, which was significantly better than that of H2-60 (45.79%) or daptomycin (55.07%) alone. The half maximal inhibitory concentrations (IC50) were 35.6 μM for H2-60 and 46.3 μM for H2-81 against the HisKA domain of YycG' protein. In conclusion, YycG inhibitors H2-60 and H2-81 exhibit excellent antibacterial and anti-biofilm activities against S. agalactiae.

Dynamic constitutional frameworks (DCFs) were synthesized and screened for biofilm inhibition or disruption. They are composed of a trialdehyde core reversibly linked to a diamine PEG connector and to a variety of neutral, anionic, or cationic heads, to generate a library of DCFs to generate multivalent dendritic architectures in the presence of Pseudomonas aeruginosa and Staphylococcus aureus. The best DCFs were always polycationic and the nature of the cationic heads significantly impact the antibiofilm activity. The best antibiofilm activity was observed for DCF3B, displaying a polyethyleneimine head. A simple inactive guanidinium functional head strongly inhibited biofilm growth when assayed as a multivalent DCF3C. Using a more advanced in vitro biofilm model of chronic wound infection, DCF3C was found significantly superior than all other DCFs. These results demonstrate the versatility and effectiveness of DCFs as low cost and efficient systems for antibiofilm disruption.

An ecofriendly and cheap photocatalyst is crucial for realizing practical photocatalysis applications. Many inorganic materials have modular structures in which individual units are responsible for different functions. [Bi2O2]2+ slabs with an α-PbO-type structure and simple halide layers are effective spacers in some layered functional materials. Previous reports have mainly discussed electronic reasons for the different photocatalytic activities of layered PbBiO2X-type materials (X = Cl, Br, I). To the best of our knowledge, nanocomposite semiconductors consisting of PbBiO2I/g-C3N4 have not been reported in the literature. In this study, PbBiO2X/g-C3N4 composites were isolated and characterized by FE-SEM-EDS, XRD, HR-XPS, TEM, PL, BET, FT-IR, and UV–vis-DRS. By degrading crystal violet (CV) and 2-hydroxybenzoic acid (HBA) in an aqueous solution under visible-light irradiation, the photocatalytic activities of PbBiO2I/g-C3N4 are discussed further. In particular, the catalytic performance illustrates the best reaction rate constants of 0.3259 h−1 using the PbBiO2I/g-C3N4 composite as the photocatalysts; these are 13.7 and 9.1 times higher than those of PbBiO2I and g-C3N4, respectively. The quenching effects of different scavenger results demonstrate that reactive O2 − plays the major role and OH, h+, and 1O2 play the minor role in CV degradation.

Surface-enhanced Raman scattering (SERS) has been a sensitive tool for the accurate detection and analysis of a wide range of molecules. In the present study, a simple and repeatable approach is developed for the fabrication of a silver nanocubes/polyelectrolyte/gold film (Ag nanocubes/PE/Au film) sandwich structure as SERS substrate. An ethanol-water mixture, instead of pure water, is used as solvent to reduce the coffee ring effect by the drop coating deposition method, such that Ag nanocubes are distributed evenly on the gold film surface with polyelectrolyte as the middle layer. In 15 repeated measurements of a 10-7 M rhodamine 6G solution, the intensity of the Raman peak at 609 cm-1 exhibits a relative standard deviation less than 20%. Significantly, the sandwich substrate exhibits excellent point-to-point repeatability and sample to sample reproducibility, and may be used for real-life quantitative analysis, as demonstrated by the rapid diagnosis of dual analytes of rhodamine 6G and crystal violet.

In this study, iron nanoparticles were synthesized by leaf extract of Plumeria and Jatropha and denoted as Pl-FeNPs and Ja-FeNPs, respectively. The synthesized nanoparticles were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (BET) and applied for the adsorption of crystal violet (CV) dye and then recycled for five cycles. The adsorption capacity of Pl-FeNPs (qmax = 125 mg/g) was higher than that of Ja-FeNPs (qmax = 10.58 mg/g). The spent iron nanoparticles were then successfully utilized as a catalyst for the degradation of CV dye in a Fenton-like process with degradation approximately 95% and 85% by Pl-FeNPs and Ja-FeNPs, respectively. Adsorption and degradation efficiency of both the nanoparticles was analyzed; Plumeria-synthesized iron nanoparticles (Pl-FeNPs) were found better in the adsorption, recycling, and degradation process as well. The adsorption process was analyzed with three models of adsorption isotherm, Langmuir, Freundlich, and Temkin isotherm, and kinetics were analyzed using pseudo-first- and pseudo-second-order kinetic. The adsorption process was fitted best with Temkin isotherm for Pl-FeNPs and Langmuir adsorption isotherm for Ja-FeNPs, while pseudo-second-order kinetics was followed by both Pl-FeNPs and Ja-FeNPs. Adsorption of CV by both of the adsorbents was found to be endothermic.

Dyes are coloured compound which are widely used in textile, painting, rubber, cosmetics, plastics and leather industry to colour their products. However, the irresponsibility of certain manufacturer results in producing dye waste and channel it to water resources had become one of the biggest challenges in water pollution. In this study, an effective solid adsorbent derived from sustainable sources for adsorption capacity study was produced which is silver nanoparticles loaded activated carbon (Ag NPs – AC) to remove crystal violet (CV) dye. Adsorption process are cost – effective, simple and flexible with various dye pollutants. Silver nanoparticles (Ag NPs) was synthesized from Clitorea Ternatea flower extract that utilizes functions as stabilizing agents for silver nitrate (AgNO3) to promotes environmental friendly with no toxic chemicals produced and loaded in activated carbon (AC). Characterization of Ag NPs was analysed using UV-Visible which correspond to peak at 408 nm and XRD analysis. Four peaks values for silver at 2θ of 38.19°, 44.43°, 64.57°, 77.43° and average crystallite size of Ag NPs and Ag NPs – AC were calculated to be 16.11 nm and 36.13 nm respectively that were obtained from XRD pattern. The adsorption capacity of Ag NPs – AC was analysed and the optimum conditions were determined using different parameters which are the Ag NPs - AC ratio (1.0 g), contact time (240 min), adsorbent dosage (30 mg) and pH of CV dye (10). The highest percentage removal of CV dye using Ag NPs – AC was recorded up to 97% at 240 min with 30 mg dosage. Ag NPs – AC as adsorbent is a promising advanced materials in removing water pollutants with viable conditions and can applied in the wastewater treatment industry.

Photocatalytic degradation of multiple organic contaminants has received extensive research attention and rational design of visible-light driven photocatalyst has been considered as an efficient approach. In this study, a visible-light Ag2O/Bi2WO6 heterostructure incorporated reduced graphene oxide (ABW-RGO) composite photocatalyst was prepared through a facile hydrothermal method for the first time and exhibited synergetic degradation behavior for contaminants in aqueous solutions. Under visible light, Tetracycline antibiotics has degraded 95.3% within only 40 min, and dye pollutants including Crystal Violet (cationic dye) and Congo Red (anionic dye) reached over 98.5% decomposition. The synthesized composite is also highly efficient in a wide pH range and multi-components system, maximizing the utilization of common sunlight, which make it suitable for industrial wastewater. The reactive oxidant species (ROS) experiment and electron spin resonance (ESR) measurement revealed the critical role of hydroxyl and superoxide radicals, clarifying the degradation pathway and mechanism analysis. The superior photocatalytic activity could be attributed to the formation of effective Z-scheme heterostructure and the excellent sorption capacity and conductivity of reduced graphene oxide. This research provides the design pathway to a novel catalyst using semiconductors composite and graphene support material, which can be extended to the energy-saving treatment of various organic pollutants.

A limitation of conventional MIP in thermal and mechanical stabilities condition, improper porosity and low adsorption capacity, give a reason to introduce a sol-gel method in molecular imprinting process recently. In this study, a synthesis of new sol-gel molecularly imprinted polymer (SG-MIP) was studied for crystal violet (CV) selective recognition. The control non-molecularly imprinted polymer (SG-NIP) was also synthesized as reference. The preparation of SG-MIP was introduced by a combination of the organic and inorganic mixture. The organic solution included the methacrylic acid, trimethylolpropane trimethacrylate, and benzoyl peroxide which are monomer, crosslinker, and initiator, respectively. The inorganic solution involved the ratio of tetraethyl orthosilicate: ethanol (1:1 v/v). The functional group analysis proved the successful synthesized SG-MIP and SG-NIP. The thermal analysis indicated high thermal stability for SG-MIP and SG-NIP, respectively. The morphology and surface analyses showed the respective different structures, surface, and porosity values between SG-MIP and SG-NIP, which influence the selectivity study and adsorption behaviour of SG-MIP toward CV adsorption. The result verified that the SG-MIP (4.900 mgg-1) has higher adsorption and higher selectivity characteristics compared to SG-NIP (4.432 mgg-1). The equilibrium data of kinetic and isotherm studies for SG-MIP and SG-NIP were well-fitted to the pseudo-second order model (R2 = 0.9997 and R2 = 0.9996) and Freundlich isotherm model (R2 = 0.9500 and R2 = 0.9764), respectively. The Freundlich isotherm was supported by the Scatchard plot instead of the Langmuir isotherm model.

The dissociation phenomenon of epizootic cultures of Moraxella was studied. The study was conducted in economic entities of Almaty region of the Republic of Kazakhstan for 233 heads of cattle with clinical signs of keratoconjunctivitis. Isolation of the causative agent of Moraxella was performed by bacteriological washes from the conjunctival sacs of the eyes of animals. The laboratory study was carried out according to the approved methodological guidelines. It was found that bacteria of the genus Moraxella dissociate when grown on a solid nutrient medium for more than 6 hours in a thermostat at 37 °C. The bacteria were studied by the following methods: staining according to White-Wilson, thermoagglutination and acriflavine assay. When evaluating the grown colonies according to White-Wilson, the optimal dilution for crystal violet was found to be 1 : 2000, and for gentian violet stain 1 : 1000. In this case, the colonies in the S-form have a dark purple color with a metallic tint, and the dissociated colonies in the R-form do not stain. In the presence of dissociated cells, precipitation (thermoagglutination), sediment formation and clearing of the supernatant fluid at 90 °C for 30 minutes were noted. The suspension of undissociated colonies remained cloudy. When weighing microbial cells isolated by a bacterial loop from individual grown colonies in a solution of acriflavine, dissociated bacteria stick together to form conglomerates. When studying the antigenic activity of the S-, R- forms of Moraxella, it was revealed that the activity of the S-antigen significantly exceeded that of the R-forms. Data on the dissociation of Moraxella cultures can be used for the development of diagnostic and prophylactic drugs against moraxellosis in cattle.

Purpose This paper aims to focus on studying the batch desorption of adsorbed crystal violet (CV) from date stones (Phoenix dactylifera), untreated (UDS) and treated using NaOH (TDS). Design/methodology/approach The process variables such as different desorbing agents, volume and concentration of the desorbing agent, contact time, dye concentration before adsorption and temperature affecting CV desorption from CV-loaded untreated date stones (CV@UDS) and treated adsorbent (CV@TDS) were optimized. The UDS and TDS were regenerated using 0.6 m HCl as eluent. Findings The HCl solution was an excellent eluent for the CV desorption from CV@UDS (96.45%) and CV@TDS (98.11%). The second-order model and the Langmuir model well exemplified experimental data with maximum desorption capacities were 63.29 mg g−1 for the CV@UDS and 243.90 mg g−1 for the CV@TDS. The calculated thermodynamic showed that the CV desorption was spontaneous, endothermic and physical. Good regeneration and reusability of UDS and TDS for the CV removal for four consecutive adsorption–desorption cycles. Practical implications This study provided a good example of reusing UDS and TDS with NaOH for fast removal of a toxic organic pollutant, CV from the wastewaters. Originality/value The use of UDS and TDS with NaOH for the first time for desorption study and their reusability to removing CV from their aqueous solutions.

The practice of releasing highly noxious textile pollutants into the water environment is a matter of great distress to the living community. In view of this issue, the study was proposed on the removal of basic fuchsin red (BFR), methylene blue (MB), and crystal violet (CV) from its solution via adsorption using the biochar synthesized from areca leaf plate waste and turmeric leaf waste biomass through pyrolysis. A detailed study on the parameters influencing the adsorption such as adsorbent dosage (0.1–1 g), pH (3–10), temperature (35–50 °C), and initial dye concentration (10–200 mg/L) were carried out. From the batch study, the best removal efficiency for the removal of BFR dye for AB biochar was found to be 80.912% for 0.3 g adsorbent dosage, 8 pH, 35 °C, and 50 mg/L initial dye concentration; MB dye was obtained as 80.80% for 50 mg/L initial dye concentration; and CV dye was obtained as 80.60% for 50 mg/L initial dye concentration. For the TB biochar, the best removal efficiency for the removal of BFR dye was obtained as 87.44% for 0.2 g adsorbent dosage, 7 pH, 35 °C, and 50 mg/L initial dye concentration; MB dye was obtained as 83.20% for 50 mg/L initial dye concentration; and CV dye was obtained as 82.60% for 0.2 g adsorbent dosage, 7 pH, 35 °C, and 50 mg/L initial dye concentration. With the help of RSM, the concurrent interactive effects of various process variables on an output response were analysed. The Langmuir isotherm model was found to be a perfect fit with R2 value of 0.98 for both AB and TB biochar bounded on BFR dye and the pseudo-second order kinetics model was found to be a perfect fit for both AB and TB biochar bounded on basic fuchsin red dye. Additionally, the efficiency of the AB and TB biochar to desorb BFR, MB, and CV dye using various eluctants such as HCl, NaOH, and de-ionized water for four regeneration cycles were studied and the HCl eluctant was found to be highly efficient in the desorption of all three dyes after four regeneration cycles.

We report a facile, green and precursor-based comparative study on the biosynthesis of zinc oxide (ZnO) nanoparticles (NPs) using anticancerous Fagonia indica as effective chelating agent. Biosynthesis was carried out using zinc sulfate and zinc acetate as precursor salts to make ZnOS and ZnOA NPs under similar experimental conditions which were characterized extensively for physical and biological properties. Scherrer equation deduced a mean crystallite size of ~23.4 nm for ZnOA NPs and ~41 nm for ZnOS NPs. The nature of the NPs was compared using UV, diffuse reflectance spectra, Fourier transform infrared spectroscopy, thermogravimetric analysis-DTA, selected area electron diffraction, EDS, zeta potential, high resolution (HR)-SEM, and HR-TEM. Detailed in vitro pharmacognostic activities revealed a significant therapeutic potential for ZnOA and ZnOS . Potential antimicrobial activities for the NPs and their nanocosmeceutical formulations are reported. ZnOA NPs were more cytotoxic to Leishmania tropica as compared to ZnOS . Significant antioxidant and protein kinase inhibition was obtained. The hemolytic assay indicated a hemocompatible nature of both ZnOA and ZnOS NPs. Catalytic degradation of crystal violet dye (CVD) by NPs was examined under different parameters (light, dark, UV). Furthermore, sonophotocatalytic degradation of CVD was also studied. Our results suggested that precursor can have a significant effect on the physical, biological, and catalytic properties of the NPs. In future, we recommend different other in vitro, in vivo biological activities, and mechanistic studies of these as-synthesized NPs.

Staphylococcus aureus causes several nosocomial and community-acquired infections in human host involving biofilm. Thus, strategies need to be explored to curb biofilm threats by either inhibiting the formation of biofilm or disintegrating the pre-existing biofilm. Towards this direction, we had already revealed the biofilm inhibiting properties of 1,4-naphthoquinone against S. aureus. In this study, we have investigated whether this compound can act on pre-existing biofilm. Hence, biofilm of S. aureus was developed first and challenged further with 1,4-naphthoquinone. Experiments such as crystal violet assay, fluorescence microscopy, and estimation of total biofilm protein were performed to confirm the biofilm disintegration properties of 1,4-naphthoquinone. The disintegration of pre-existing biofilm could be attributed to the generation of reactive oxygen species (ROS). To investigate further, we observed that extracellular DNA (eDNA) was found to play an important role in holding the biofilm network as DNaseI treatment could cause an efficient disintegration of the same. To examine the effect of ROS on the eDNA, we exposed pre-existing biofilm to either 1,4-naphthoquinone or a combination of both 1,4-naphthoquinone and ascorbic acid for different length of time. Post-incubation, ROS generation and the amount of eDNA associated with the biofilm were determined wherein an inversely proportional relationship was observed between them. The result indicated that with the increase of ROS generation, the amount of eDNA associated with biofilm got decreased substantially. Thus, the results indicated that the generation of ROS could degrade the eDNA thereby compromising the integrity of biofilm which lead to the disintegration of pre-existing biofilm.

This work aimed to evaluate antiviral, antibacterial and anti-quorum sensing effects of a lyophilized aqueous pine resin extract. The pine resin toxicity was evaluated by a crystal violet assay at 492 nm for Hep-2 cells and the trypan blue method for P3HR1. The cytotoxicity expressed in CC50 was 12.5 mg/ml and 0.23 mg/ml on Hep-2 and P3HR1 cells, respectively. The antiviral effect was obtained at 4 mg/ml against coxsackievirus B4 (CVB4). Using the diffusion method discs for the antibacterial activity, the extract was more active against Gram+ than Gram−. Inhibition zones of 22 mm were obtained at a 275 mg/ml concentration. Inhibition of violacein production by pine resin extract was tested using Chomobacterium violaceum 026 (CV026) in a medium supplemented with acyl-homoserine lactone (AHL); cytotoxicity was evaluated toward Artemia and its protecting effect against Vibrio harveyi BB120 and then AHL degradation was studied. Results showed that pine resin inhibited violacein production by CV026, was not toxic for Artemia and protected it against Vibrio harveyi BB120; AHL was degraded with inhibition areas from 9.6, 11.03 and 10.26 to 12.34 mm at the contact times of the mixtures “resin-AHL” respectively at 0 h, 4 h 24 h and 72 h. This study constitutes a confirmation of aqueous extract pine resin as antibacterial, by anti-quorum sensing pathway and antiviral efficacy.

The utilization of rosin to fabricate functional polymers has attracted great attention due to its unique structure and property. Herein, we prepared a new type of carboxyl-containing cross-linked rosin microspheres (CCRMs) using a renewable-resource rosin as the raw material through the suspension polymerization. For comparative purpose, vanillin methacrylate (VMA), styrene (St) and isobornyl methacrylate (IBOMA) were separately used to replace DAGMA as monomer for the preparation of microspheres. Our results indicated that the obtained porous CCRMs showed a broad size distribution ranging from mesopores (3–50 nm) to macropores (> 50 nm), whereas the counterparts derived from VMA, St or IBOMA showed a powder state. Moreover, the CCRMs exhibited moderately high thermal stability. The integration of DAGMA into polymer microspheres provided CCRMs with excellent adsorption ability, which exhibited robust selective cationic dye (e.g., methylene blue (MB) and crystal violet (CV)) adsorption from waste aqueous solution. The adsorption process was fitted well with the Langmuir isotherm and the pseudo-second-order kinetic model. The maximum adsorption capacity was observed to be 602.4 mg/g for CV at 40 °C, and 512.8 mg/g for MB at 20 °C. In general, the high dye adsorption properties suggest that CCRMs may be highly efficient in adsorption selectivity for some cationic dyes.

We present the excellent and selective activity against human cancer cells and pathogens by double-layer carbon-encapsulated silver nanoparticles ([email protected]) and monolayer carbon-encapsulated silver nanoparticles ([email protected]). [email protected] were synthesized via a modified solvothermal approach, whereas [email protected] were prepared by exfoliation of the outer carbon layer of [email protected] The physicochemical structures and properties of the [email protected] and [email protected] are thoroughly examined; the carbon layer is found to ensure the needful release of Ag+ ions from the core Ag nanoparticles, and improve the biocompatibility and selectivity of NPs to kill the cancer cells. Hence, the [email protected] and [email protected] are substantiated to be beneficial for controlling the overtoxicity caused by unstable bare AgNPs and achieving the targeted actions. The Ag+ ions exhibit their toxic effects against cancer cells or pathogens chiefly through the reactive oxygen species (ROS) generation. The Ag+-ion release and ROS generation of the [email protected] are found greater than those of the [email protected] because of the synergistic effect of the reduced thickness of carbon layer and increased specific surface area. The [email protected] and [email protected] were applied against cancer cells (K562 and Hep3B), normal cells (LO2), and pathogens in vitro. The [email protected] exhibit greater dose- and time-dependent late apoptosis of cancer cells than the [email protected], and reduce the viability of cancer cells more effectively than the [email protected] The crystal violet assay explicitly displays that the as-prepared samples exhibit preferential attack on cancer cells. In the analysis of apoptosis associated proteins, caspase-3 and PARP as markers, the protein expression was visible only for the cancer cells asserting that the prepared [email protected] and [email protected] act selectively, invading only the cancer cells. Moreover, the [email protected] exhibit a larger linear inhibition zone than the [email protected] against both Gram negative and Gram positive pathogenic bacterial stains in bactericidal activity probes.

Dyes are used in many applications with their consequent discharge into aquatic environments. Alternative methods of pollutant removal, such as biosorption, are currently necessary to achieve an efficient, low-cost, and environmentally friendly process. The biomasses, living and dead, from the microalga Phaeodactylum tricornutum were studied to determine their ability to remove three dyes, Methylene Blue, Crystal Violet and Safranin from seawater. The removal properties were determined as a function of contact time, initial dye concentrations, and pH, and characterized with the determination of the point of zero charge (pHPZC) and FTIR. The highest removal capacity was obtained with crystal violet (66.4 mg g−1), without significant differences between both biomasses and following a pseudo-fourth order kinetics, indicating a high affinity for said dye. Maximum removal capacity for methylene blue was 18.9 mg g−1 with significant differences between both biomasses until the concentration of 10 mg L−1, the dead biomass being more effective since this dye would present difficulties to enter the living cells. The kinetics was of pseudo-third order. Safranin obtained a removal capacity of 19.6 mg g−1 with also significant differences between both biomasses up to a concentration

En el presente trabajo se sugiere la reutilizacion del fieltro de fibra de carbon activado (FFCA) para la remocion del colorante cationico violeta de metilo, tambien llamado cristal violeta (CV), presente en una solucion sintetica. La estructura morfologica de la FFCA se analizo mediante Microscopia Electronica de Barrido de Alta Resolucion (MEBAR). Los procesos de remocion del colorante se realizaron de manera discontinua a temperatura ambiente y pH de 10, mediante el reuso de la FFCA hasta 10 veces. Posterior a cada proceso de remocion, la FFCA se sometio a un tratamiento termico (calcinacion) que permitio convertir el colorante adsorbido en CO y CO2 y extender el tiempo de vida util de la FFCA. Los resultados muestran que el proceso de adsorcion sigue la isoterma de Langmuir con cinetica de pseudo primer orden, lo cual sugiere que se llevo a cabo una quimisorcion por la atraccion covalente entre los grupos carbonilo de la FFCA y la especie cationica del colorante. La novedad del trabajo se centra en la reutilizacion de la FFCA hasta por 10 ciclos de remocion con alto porcentaje de remocion, lo cual puede llevar a una disminucion en los costos de adquisicion del material adsorbente.