Efficient Antimicrobial Activity Research Articles

Chemically engineered polyethylenimine conjugates for mannose receptor-mediated gene delivery with potential antimicrobial and anticancer activity

Polyethylenimines exhibit unique intrinsic properties, which make them potential gene delivery agents. However, nonspecific interactions and cytotoxicity in the cells/tissues have significantly hampered their use in clinical applications. To subside these concerns, plant-based cyclitols, shikimic and quinic acids, have been tethered to polyethylenimine (PEI) to fabricate shikimoyl-PEI (SP) and quinoyl-PEI (QP) conjugates under mild coupling conditions. On interactions with plasmid DNA, the size and zeta potential of SP and QP complexes were found in the range of ∼245–158 nm and ∼ +22–10 mV, respectively. Subsequent assessment of these complexes revealed that cytocompatibility (∼90%–94%) and transfection efficiency (∼90% cells transfected) were significantly higher as compared to the native PEI/pDNA and Lipofectamine/pDNA complexes. Further, a higher degree of pDNA release was also obtained from SP/DNA and QP/DNA complexes. A decrease in GFP expression was observed in a competitive assay on RAW 264.7 cells, which reflected receptor-mediated internalization of SP and QP/DNA complexes. Besides, both SP and QP conjugates also displayed efficient antimicrobial activity against differential pathogenic strains of bacteria. Of these conjugates, QP conjugates exhibited promising anticancer activity against variable cell lines such as RAW 264.7, MCF-7, HepG2 cells. Altogether, these results advocate the promising potential of SP and QP conjugates as efficient gene delivery agents having effective antimicrobial and anticancer competence.

Preparation and characterization of carvacrol/soybean protein isolate composite film with efficient antimicrobial and antioxidant activities and its application in grape preservation

There is an urgent need for a simple and effective method to enhance the freshness of fruits during transportation. In this study, we developed a composite antibacterial film (CAR film) using carvacrol and soy protein isolate (SPI). The mechanical properties, hydrophobicity, antibacterial activity, and antioxidant capacity of the film were characterized. The results demonstrated that, compared to the soy protein isolate film, the film with 2.5 % carvacrol content exhibited superior mechanical properties (tear strength decreased by approximately 37 %, elongation at break increased by about 108 %), hydrophobicity (water vapor permeability decreased by 38 %), antibacterial activity (inhibition zone diameters against E. coli and S. aureus were 14.21 mm and 11.83 mm, respectively), antioxidant capacity (increased by 5 to 6 times), and biocompatibility (cell survival rate exceeded 90 %). Grape preservation experiments further confirmed that the CAR film effectively prolongs shelf life. Therefore, CAR film is a promising packaging material for fruit preservation.

CeO2-Coated Porphyrin-Based Porous Organic Polymers as Nanozymes for Efficient Antimicrobial Activity

CeO₂-Coated Porphyrin-Based Porous Organic Polymers as Nanozymes for Efficient Antimicrobial Activity

Construction S-scheme Bi4O5Br2/BiOI composite for accelerated charge separation and enhanced photocatalytic degradation and antibacterial performance

Photocatalytic technology is an effective solution to environmental pollution problems. The development of efficient photocatalysts is of great practical significance for environmental remediation. In this study, Bi4O5Br2/BiOI S-scheme heterojunction was successfully prepared by solvothermal and facile room-temperature deposition methods. The optimum sample 30 % Bi4O5Br2/BiOI (BrI-30) could degrade 90.5 % methyl orange (MO) in 60 min and 71.6 % tetracycline (TC) in 90 min under LED light irradiation, and it could completely inactivate Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in 30 min. Bi4O5Br2/BiOI composites exhibited efficient degradation and antimicrobial activities, which were principally ascribed to the formation of the heterojunction interface between Bi4O5Br2 and BiOI facilitating the migration of photo-generated carriers. The effects of different factors on the photo-degradation properties were systematically investigated. In addition, mass spectrometry (MS) has been accustomed to detecting the intermediates formed when TC degraded and possible pathways for TC degradation were proposed. Eventually, based on energy-band analysis, the mechanism of removing pollutants and inactivating bacteria in Bi4O5Br2/BiOI composites was proposed. This study provides a novel solution for treating organic pollutants and bacteria in water bodies, which has practical applications in environmental remediation.

Photocatalytic Ag-MOF confers efficient antimicrobial activity to modified polyvinyl alcohol films

Antimicrobial packaging films are an effective means to avoid food infections. PVA has good film-forming and mechanical properties, but its water resistance and antimicrobial properties are insufficient. In this study, a rod-shaped Ag-MOF with photocatalytic properties was synthesized as an antimicrobial agent by a hydrothermal method using citrate esterified PVA as a film-forming substrate. The MICs of Ag-MOF against Escherichia coli and Staphylococcus aureus were 16 μg/mL and 32 μg/mL, respectively, and it had good biocompatibility. Under blue light irradiation, Ag-MOF induced the production of ROS, which increased the inhibition rate by more than 83.78%. The antimicrobial mechanism experiments showed that it caused irreversible damage to the bacterial cell membrane through the synergistic effect of Ag+ and ROS. The best mechanical properties of the films were obtained at 3% citric acid content, with the water vapor transmission rate, water solubility and swelling rate reduced by 0.19 g·mm·m−2·h−1·kPa−1, 65.33% and 11.26%, respectively. The antimicrobial rate of the composite film could reach more than 98% by adding only 1 MIC of Ag-MOF. In conclusion, photocatalytic antimicrobial agents have great potential for application in food packaging.

Green synthesis of Bi2O3, MnO2 and their nanocomposite (Bi2O3/MnO2) for efficient photodegradation and antimicrobial activity

An eco-friendly green synthesis approach was used to synthesize Bi2O3, MnO2, and Bi2O3/MnO2 nanocomposite in order to comprehend the effect of nanocomposite on the photocatalytic and antibacterial activity. The structural parameters of as prepared samples were confirmed using X-ray diffraction analysis (XRD). Scherrer formula was applied to find out crystallite size, which ranged from 8 nm to 13 nm. XRD confirmed the geometrical structure of Bi2O3, MnO2 and Bi2O3/MnO2 nanocomposite showing monoclinic structure. The FTIR peaks also confirm the successful synthesis of Bi2O3/MnO2 nanocomposite. SEM of Bi2O3/MnO2 nanocomposite revealed that nanoparticles of Bi2O3 are developed on MnO2 granules. In UV–Vis spectroscopy, absorption maxima showed in the range of 200 nm to 400 nm and band gap ranging from 2.4 eV to 3.4 eV. The antibacterial activity of Bi2O3, MnO2, and Bi2O3/MnO2 nanocomposite was investigated against two gram negative-bacteria (Pseudomonas and Escherichia coli) at 10 mg and 20 mg concentration using disk diffusion method. The zone of inhibitions against Escherichia coli at 10 mg and 20mgl were 22 mm and 26 mm while against Pseudomonas were 28 mm and 33 mm for Bi2O3/MnO2 nanocomposite. Bi2O3/MnO2 composite shows better result as compared to Bi2O3 and MnO2. Photocatalytic activity was carried out using Bi2O3, MnO2, and Bi2O3/MnO2 as photocatalyst for the removal of malachite green (MG) and methylene blue (MB). For Malachite Green (MG), the maximum degradation efficiency of Bi2O3, MnO2, and Bi2O3/MnO2 nanocomposite was 96 %, 97 % and 98 % respectively. For methylene blue (MB), the maximum degradation efficiency of Bi2O3, MnO2, and Bi2O3/MnO2 nanocomposite was 95 %, 97 % and 98 % respectively. This work concludes that Bi2O3/MnO2 nanocomposite enhances the degradation efficiency and antibacterial potential.

Choline-amino acid-based polyionic liquids and ionogels for antimicrobial infections

Microbial infections pose a serious threat to human health. Although antibiotics from various sources continue to be discovered, antibiotics often induce resistance in microorganisms. Therefore, the development of novel antimicrobial agents or materials based on new mechanisms remains an urgent need. Herein, a series of choline-amino acid polyionic liquids ([Cho][AA] PILs) and the corresponding composite ionogels (BC/PILs) made from [Cho][AA] PILs and bacterial cellulose (BC) were prepared by ex situ method. The antimicrobial properties of PILs and BC/PIL ionogels, as well as the mechanical, conductive and biocompatible properties of BC/PIL ionogels were investigated. The resultant PILs and BC/PIL ionogels exhibited efficient antimicrobial activity against Gram-positive bacteria, Gram-negative bacteria and fungi. Moreover, the concentration, chirality, hydrophilic and hydrophobic properties of [Cho][AA] PILs have a significant impact on the antimicrobial performance of these materials. Among them, D-type phenylalanine-based PILs (D-P[Cho][Phe]) and BC/PIL ionogels based on the highest concentration of D-type PILs (D-BC/PIL-1.6 ionogels) showed the strongest antimicrobial properties against microorganisms. The MIC and MBC of D-P[Cho][Phe] could be as low as 32±1.6 mmol L-1 and 64±3.2 mmol L-1. Morover, D-P[Cho][Phe] displayed the fastest bactericidal rate and killed bacteria within 2 h. In addition, BC/PIL ionogels with excellent mechanical and conductive properties could be achieved by controlling the concentration and type of [Cho][AA] PILs. Serine-based ionogels (BC/P[Cho][Ser]) possessed the highest mechanical strength. BC/PIL-1.6 ionogels showed the highest conductivity. More significantly, [Cho][AA] PILs and BC/PIL ionogels exhibited good biocompatibility. These results provided novel ideas and a practical basis for the development of new antimicrobial materials and suggested the promising application potential of [Cho][AA] PILs and their corresponding BC/PIL ionogels in the biomedical field.

Copper and silver nano-schiff base complexes: Efficient catalysts for triazole synthesis and antimicrobial assessment

1,2,3-Triazoles are one of the most important nitrogen-containing five-membered heterocycles and have a wide range of applications in pharmaceuticals, chemical biology, and industry. Therefore, the development of facile and straightforward methodology for the synthesis of 1,2,3-triazoles is of noteworthy interest. Click chemistry represents the most facile, easy and one pot reaction method to synthesize catalyzed azide–alkyne cycloaddition reaction. Nano-scaled bis(2‑hydroxy-1-naphthylmethylidene) ethane-1,2-diamine copperII [CuSB1] and nano-silver ethane-1,2-diamine bis(2-hydroxy-1-naphthylmethylidene) [AgHSB2] complexes where H2SB= 1,2-diamino ethane-N,N’-bis(2-hydroxy-1-naphthylmethylidene), were synthesized utilizing ultrasonic green method. The catalysts were examined by elemental analyses, molar conductance, and spectrophotometric tests. The optimized geometrical structures of H2SB, [CuSB1], [AgHSB2], and HOMO–LUMO representations were performed by Cluster calculations using DMOL3 program. TEM images showed narrower morphology and regular nanostructures of the catalysts. CuSB1] and [AgHSB2] exhibit efficient catalytic activity to prepare different triazoles (3–8). using single-pot selective cycloaddition reaction within very short time and excellent yield without presence of biproducts. The complexes [CuSB1], [AgHSB2] and the triazoles 3, 4, as representative examples, have efficient antimicrobial activity making them promising drugs for treating the bacterial and fungal infections.

Rapid Membrane-Penetrating Hybrid Peptides Achieve Efficient Dual Antimicrobial and Antibiofilm Activity through a Triple Bactericidal Mechanism.

Antimicrobial peptides (AMPs) are a type of biomaterial used against multidrug resistant (MDR) bacteria. This study reports the design of a peptide family rich in tryptophan and lysine obtained by optimizing a natural AMP using single factor modification and pheromone hybridization to expedite the penetration and improve the antimicrobial activity of AMPs. S-4, L-4, and P-4 showed α-helical structures, exhibited extremely fast membrane penetration rates in vitro, and could kill MDR bacteria efficiently within 30 min. Intracellular fluorescence localization suggested rapid membrane-penetrating of AMPs within 1 min, making it more difficult for bacteria to develop resistance. Furthermore, they could effectively inhibit and destroy bacterial biofilms with dual antimicrobial and antibiofilm activity. In the treatment of skin infections caused by MDR-Acinetobacter baumannii in vivo , AMPs could effectively alleviate inflammation without toxic side effects. Additionally, the triple antimicrobial damage of AMPs was described in detail. AMPs rapidly penetrate the cell membrane, inducing cell membrane damage, triggering oxidative damage with a storm of reactive oxygen species and leading to bacterial death through leakage of cellular contents by complexing with DNA. The multiple damage is an important means by which AMPs can prevent bacterial resistance adequately.

Metal-polyphenol coordination nanosheets with synergistic peroxidase-like and photothermal properties for efficient antibacterial treatment

Bacterial infections pose a serious threat to human health and socioeconomics worldwide. In the post-antibiotic era, the development of novel antimicrobial agents remains a challenge. Polyphenols are natural compounds with a variety of biological activities such as intrinsic antimicrobial activity and antioxidant properties. Metal-polyphenol obtained by chelation of polyphenol ligands with metal ions not only possesses efficient antimicrobial activity but also excellent biocompatibility, which has great potential for application in biomedical and food packaging fields. Herein, we developed metal-polyphenol coordination nanosheets named copper oxidized tannic acid quinone (CuTAQ) possessing efficient antibacterial and anti-biofilm effects, which was synthesized by a facile one-pot method. The synthesis was achieved by chelation of partially oxidized tannic acid (TA) with Cu2+ under mild conditions, which supports low-cost and large-scale production. It was demonstrated that CuTAQ exhibited high antibacterial activity via disrupting the integrity of bacterial cell membranes, inducing oxidative stress, and interfering with metabolism. In addition, CuTAQ exhibits excellent peroxidase catalytic activity and photothermal conversion properties, which play a significant role in enhancing its bactericidal and biofilm scavenging abilities. This study provides insights for rational design of innovative metal-polyphenol nanomaterials with efficient antimicrobial properties.

Efficient drug delivery potential and antimicrobial activity of biocompatible hydrogels of dextrin/Na-alginate/PVA

Ceftriaxone sodium belongs to the third-generation cephalosporin group and is used intramuscular and intravenous route as a broad-spectrum antibiotic. This research aims to prepare biocompatible hydrogels for targeted delivery of ceftriaxone sodium by parental route. Different proportions of polymers (natural and synthetic) in the presence of cross-linker were synthesized by solvent casting method. Ceftriaxone sodium was loaded in hydrogels in different concentrations and its drug release behavior was evaluated along with swelling and biodegradation analysis. The characterization of hydrogel was done by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) to analyze surface morphology and functional groups involved in the formation of dextrin/Na-alginate/PVA hydrogels loaded with the drug. Thermogravimetric analysis (TGA) was confirmed by thermal stability and degradation pattern of loaded and unloaded hydrogels. The drug-loaded samples presented promising antimicrobial activity against S. aureus and P. multocida and their cytotoxic nature was also studied. Drug release analysis using simulated intestinal fluid (SIF) and phosphate buffer saline(PBS) for the circulatory system shows the consistent release of the drug. The findings unveiled the development of a biocompatible and innovative hydrogel, which has potential advantages for biomedical application, particularly in enhancing the therapeutic efficacy of ceftriaxone sodium drug.

Green Synthesis and Characterization of Biologically Synthesized and Antibiotic-Conjugated Silver Nanoparticles followed by Post-Synthesis Assessment for Antibacterial and Antioxidant Applications.

The paper presents the antibacterial and antioxidant activities of silver nanoparticles (AgNPs) when conjugated with two antibiotics levofloxacin and ciprofloxacin as well as biologically synthesized nanoparticles from Moringa oleifera and Curcuma longa. Leaves of Moringa and powder of Curcuma were used in the green synthesis of silver nanoparticles. Ultraviolet-visible spectroscopy (UV), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) were used for the characterization of the synthesized silver nanoparticles. Comparison of levofloxacin and ciprofloxacin and their conjugated AgNPs was also studied for antibacterial and antioxidant activity. The synthesis of Moringa-AgNPs, turmeric-AgNPs, levofloxacin-AgNPs, and ciprofloxacin-AgNPs was confirmed by UV spectroscopy. An absorption peak value of 400-450 nm was observed, and light to dark brown color indicated the synthesis of AgNPs. Moringa-AgNPs revealed high antioxidant activity (80.3 ± 3.14) among all of the synthesized AgNPs. Lev-AgNPs displayed the highest zone of inhibition for Staphylococcus aureus, while in Escherichia coli, Cip-AgNPs showed high antibacterial activity. Furthermore, AgNPs synthesized using green methods exhibit high and efficient antimicrobial activities against two food-borne pathogens. Biologically synthesized nanoparticles exhibited antibacterial activity against E. coli (13.73 ± 0.46 with Tur-AgNPs and 13.53 ± 0.32 with Mor-AgNPs) and S. aureus (14.16 ± 0.24 with Tur-AgNPs and 13.36 ± 0.77 with Mor-AgNPs) by using a well diffusion method with significant shrinkage and damage of the bacterial cell wall, whereas antibiotic-conjugated nanoparticles showed high antibacterial activity compared to biologically synthesized nanoparticles with 14.4 ± 0.37 for Cip-AgNPs and 13.93 ± 0.2 for Lev-AgNPs for E. coli and 13.3 ± 0.43 for Cip-AgNPs and 14.33 ± 0.12 for Lev-AgNPs for S. aureus. The enhanced efficiency of conjugated silver nanoparticles is attributed to their increased surface area compared to larger particles. Conjugation of different functional groups contributes to improved reactivity, creating active sites for catalytic reactions. Additionally, the precise control over the size and shape of green-synthesized nanoparticles further augments their catalytic and antibiotic activities.

In-situ forming PLGA implants: Towards less toxic solvents

In-situ forming poly(lactic-co-glycolic acid) (PLGA) implants offer a great potential for controlled drug delivery for a variety of applications, e.g. periodontitis treatment. The polymer is dissolved in a water-miscible solvent. The drug is dissolved or dispersed in this solution. Upon contact with aqueous body fluids, the solvent diffuses into the surrounding tissue and water penetrates into the formulation. Consequently, PLGA precipitates, trapping the drug. Often, N-methyl-2-pyrrolidine (NMP) is used as a water-miscible solvent. However, parenteral administration of NMP raises toxicity concerns. The aim of this study was to identify less toxic alternative solvent systems for in-situ forming PLGA implants. Various blends of polyethylene glycol 400 (PEG 400), triethyl citrate (TEC) and ethanol were used to prepare liquid formulations containing PLGA, ibuprofen (as an anti-inflammatory drug) and/or chlorhexidine dihydrochloride (as an antiseptic agent). Implant formation and drug release kinetics were monitored upon exposure to phosphate buffer pH 6.8 at 37 °C. Furthermore, the syringeability of the liquids, antimicrobial activity of the implants, and dynamic changes in the latter’s wet mass and pH of the release medium were studied. Importantly, 85:10:5 and 60:30:10 PEG 400:TEC:ethanol blends provided good syringeability and allowed for rapid implant formation. The latter controlled ibuprofen and chlorhexidine release over several weeks and assured efficient antimicrobial activity. Interestingly, fundamental differences were observed concerning the underlying release mechanisms of the two drugs: Ibuprofen was dissolved in the solvent mixtures and partially leached out together with the solvents during implant formation, resulting in relatively pronounced burst effects. In contrast, chlorhexidine dihydrochloride was dispersed in the liquids in the form of tiny particles, which were effectively trapped by precipitating PLGA during implant formation, leading to initial lag-phases for drug release.

An Eco-friendly Approach to ZnO NP Synthesis Using Citrus reticulata Blanco Peel/Extract: Characterization and Antibacterial and Photocatalytic Activity.

Emission of greenhouse gases and infectious diseases caused by improper agro-waste disposal has gained significant attention in recent years. To overcome these hurdles, agro-waste can be valorized into valuable bioactive compounds that act as reducing or stabilizing agents in the synthesis of nanomaterials. Herein, we report a simple circular approach using Citrus reticulata Blanco (C. reticulata) waste (peel powder/aqueous extract) as green reducing and capping/stabilizing agents and Zn nitrate/acetate precursors to synthesize ZnO nanoparticles (NPs) with efficient antimicrobial and photocatalytic activities. The obtained NPs crystallized in a hexagonal wurtzite structure and differed clearly in their morphology. UV-vis analysis of the nanoparticles showed a characteristic broad absorption band between 330 and 414 nm belonging to ZnO NPs. Fourier transform infrared (FTIR) spectroscopy of ZnO NPs exhibited a Zn-O band close to 450 cm-1. The band gap values were in the range of 2.84-3.14 eV depending on the precursor and agent used. The crystallite size obtained from size-strain plots from measured XRD patterns was between 7 and 26 nm, with strain between 16 and 4%. The highly crystalline nature of obtained ZnO NPs was confirmed by clear ring diffraction patterns and d-spacing values of the observed lattice fringes. ZnNPeelMan_400 and ZnNExtrMan showed good stability, as the zeta potential was found to be around -20 mV, and reduced particle aggregation. Photoluminescence analysis revealed different defects belonging to oxygen vacancies (VO+ and VO+2) and zinc interstitial (Zni) sites. The presence of oxygen vacancies on the surface of ZnAcExtrMan_400 and ZnAcPeelMan_400 increased antimicrobial activity, specifically against Gram-negative bacteria Escherichia coli (E. coli) and Salmonella enteritidis (S. enteritidis). ZnNExtrMan with a minimal inhibitory concentration of 0.156 mg/mL was more effective against Gram-positive bacteria Staphylococcus aureus (S. aureus), revealing a high influence of particle size and shape on antimicrobial activity. In addition, the photocatalytic activity of the ZnO NPs was examined by assessing the degradation of acid green dye in an aqueous solution under UV light irradiation. ZnAcPeelMan_400 exhibited excellent photocatalytic activity (94%) within 90 min after irradiation compared to other obtained ZnO NPs.

Facile synthesis and grafting of N2O2‐Cu(II) Schiff base complex onto graphene oxide surface: Aspects of its antimicrobial, anticancer, antiCOVID‐19 and photodegradation of methylene blue

AbstractIn this study, a facile synthesis and grafting method is reported for tetradentate Cu(II) Schiff base complex onto the surface of graphene oxide (GO). The Schiff base Cu‐complex was synthesized through the condensation reaction between 2,3‐diamino pyridine and 2‐hydroxy‐1‐naphthaldehyde, followed by the addition of Cu(II) ion to afford N2O2‐Cu(II) complex. The GO was prepared through a modified Hummers’ method and characterized using various spectroscopic and microscopic techniques. The Schiff base Cu‐complex was then grafted onto the surface of GO via a simple solution‐phase reaction, resulting in the formation of N2O2‐Cu(II) Schiff base/GO composite. The fabricated composite was characterized using FTIR spectroscopy, UV–vis, X‐ray diffraction (XRD), and scanning electron microscopy (SEM). Importantly, the prepared N2O2‐Cu(II) Schiff base complex exhibited excellent DNA interaction as well as efficient antimicrobial and anticancer activities. Additionally, it demonstrated potent anticancer activity against hepatocellular carcinoma cells (HepG‐2), and colon cancer cells (HCT‐116) and exhibited promising activity against the COVID‐19 receptor (PDB ID: 6LU7) along with the human DNA receptor (PDB ID: 1BNA). Furthermore, this fabricated heterogeneous catalyst showed enhanced photodegradation of MB with ≈92% conversion and four times recyclability. The overall results suggest that the Cu(II) Schiff base/GO composite has potential applications in various medical and environmental fields, including photodegradation/elimination of harmful organic dyes for water treatment applications.

CuI Promoted Efficient Synthesis and Antimicrobial Activity of Substituted 8,8-Dimethyl-5-phenyl-2-(pyrazin-2-yl)-5,7,8,9-tetrahydro-6H-[1,3,4]thiadiazolo[2,3-b]quinazolin-6-one

In present study, an efficient synthesis of substituted 5,7,8,9-tetrahydro-6H-[1,3,4]thiadiazolo[2,3-b]quinazolin-6-one compounds promoted by CuI as catalyst was carried out. These derivatives were obtained from 1,3,4-thiadiazol-2-amine, dimedone and substituted aromatic aldehyde in presence of CuI in ethanol as solvent at 70 ºC. Initially, 1,3,4-thiadiazol-2-amine was synthesized from pyrazine-3- carboxylic acid reacted with thiosemicarbazide in the presence of 50% H2SO4 in acetonitrile at 70 ºC. All the newly obtained derivatives were evaluated by the spectroscopic techniques such as 1H NMR, 13C NMR and LCMS and structural determination of titled analogous were analyzed by elemental analysis. The antibacterial activities of the newly synthesized compounds were also screened.

Facile bio-inspired synthesis of polysaccharide-mediated zinc oxide nanoparticles and their efficient antimicrobial and photocatalytic activity

BackgroundGreen synthesis for nanomaterials, an eco-friendly and sustainable technology, has gained prominence in recent decades, especially in dye removal. The widespread use of toxic organic dyes in various industries has become a significant concern for human health, mainly when these dyes contaminate wastewater. This current study focuses on the prevalent use of hazardous dyes, known for their ecotoxicity, and the challenge of effectively removing these pollutants from wastewater. AimThe primary goal is to achieve a bio-inspired synthesis of zinc oxide nanoparticles using polysaccharides as mediators. This synthesis is designed to enhance the antimicrobial attributes of the nanoparticles and facilitate the photocatalytic degradation of organic dyes. Notably, polysaccharides serve a dual purpose as both a reducing and stabilizing agent for synthesizing ZnO nanoparticles. Significant findingsThe XRD distinctive lattice pattern peaks, such as (1 0 0), (0 0 2), and (1 0 1), affirmed the pure formation of the ZnO structure with a hexagonal wurtzite crystal structure. The chemical composition and product purity of green-produced SB-ZnO NPs were assessed through SEM and XPS analysis. The study then utilized polymer-mediated green-synthesized ZnO NPs for the photocatalytic degradation of Congo red and crystal violet under visible light irradiation. The results demonstrated remarkable photocatalytic activity, with around 88.2% of Congo red dye degradation observed within 80 min of visible light exposure. Notably, Congo red exhibited higher catalytic efficiency compared to crystal violet dye. The antimicrobial activity of SB-ZnO NPs obtained through green synthesis was also investigated. The antimicrobial study revealed the formation of zones against both gram-positive and gram-negative bacterial pathogens. These bioassay metal oxides are recognized for their potential in environmental remediation due to their low cost, stability, efficiency, and minimal environmental impact. The enhanced photocatalytic efficiency of polymer-metal nanocomposites shows significant potential in propelling the utilization of photocatalysts for environmental applications, specifically in wastewater treatment and bactericidal processes.

Solanum tuberosum tuber-driven starch-mediated green-hydrothermal synthesis of cerium oxide nanoparticles for efficient photocatalysis and antimicrobial activities

In this study, we are reporting for the first time the utilization of Solanum tuberosum tuber-driven, starch-mediated, green-hydrothermally synthesized cerium oxide nanoparticles (G-CeO2 NPs) for the antibacterial activity and photodegradation of cationic (methylene blue, MB) and anionic (methyl orange, MO) dyes separately and in combination, aimed at environmental remediation. The XRD analysis confirms the fluorite structure of G-CeO2 NPs, displaying an average crystallite size of 9.6 nm. Further, XPS confirms the existence of 24% of Ce3+ oxidation states within G-CeO2 NPs. Morphological studies through FE-SEM and TEM reveal that starch-driven OH− ion production leads to a high percentage of active crystal facets, favoring the formation of Ce3+-rich CeO2 NPs. Photocatalytic experiments conducted under UV-A illumination demonstrate the superior degradation performance of G-CeO2 NPs, with MB degradation reaching 93.4% and MO degradation at 77.2% within 90 min. This outstanding catalytic activity is attributed to the mesoporous structure (pore diameter of 5.63 nm) with a narrow band gap, a large surface area (103.38 m2g-1), and reduced charge recombination, as validated by BET, UV–visible, and electrochemical investigations. The identification of photogenerated intermediates is achieved through LCMS, while the mineralization is monitored via total organic carbon analysis. Moreover, the scavenging experiments point towards the involvement of reactive oxygen species in organic oxidation, demonstrating efficiency over five consecutive trials. Additionally, G-CeO2 NPs exhibit potent antibacterial activity against both gram-positive and gram-negative bacteria. This study presents an innovative, and efficient approach to environmental remediation, shedding light on the potential of G-CeO2 NPs in addressing environmental pollution challenges.

An efficient synthesis, characterization, antimicrobial and anticancer activities of azo dyes derived from eugenol

A new series of azo dyes of the naturally occurring phenol i.e., eugenol (4-allyl-2-methoxyphenol) was produced by the conventional method. For the synthesis of azo compounds, diazonium salts were coupled with eugenol. Six substituted aryl-azo-eugenol derivatives (EU (a) to EU (f)) were synthesized and confirmed their structures with 1H NMR,13C NMR, FT-IR and Mass spectroscopy. All newly synthesized azo dyes of eugenol were evaluated for their in vitro antibacterial activity against S. aureus, S. pyogenus, E. coli, P. aeruginosa strains and in vitro antifungal activity against C. albicans, A. niger and A. clavatus strains by using micro broth dilution method. The results indicate that the synthesized azo dyes of eugenol display variable inhibitory effects on the growth of bacterial and fungal strains. Further, all compounds were evaluated for their anticancer activity against human breast cancer cell lines MDA-MB-241, the compound EU(d) displays excellent anticancer activity.

Eco Friendly Synthesis of Silver Oxide Nanoparticles from Borassus Flabellifer Fiber and Its Antibacterial Activity Against Representative Micro Organisms

Abstract The present study reports an easy eco-friendly, cost efficient, and rapid method for the synthesis of silver nanoparticles (Ag NPs) using palm sprouts as reducing cum capping agent. Green synthesis of silver nanoparticles was successfully performed using palm sprouts plant extract via a simple and cheaper eco-friendly method. Palm sprouts extract reduces silver nitrate to silver nanoparticles. The resulting materials were analyzed by Fourier-transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and X-ray Diffraction (XRD) analysis. FT-IR spectrum confirms the presence of various functional groups in the active biomolecules, it acts as a capping agent for the nanoparticles. The morphology of this sample was analyzed through SEM and the presence of silver was confirmed accordingly. The green synthesized Ag NPs exhibited an excellent antibacterial activity against E. coli and P. aeruginosa and B. subtilis and S. aureus besides imparting efficient antimicrobial activity against pathogenic bacteria as well.