Green synthesis of ZnO nanoparticles using orange fruit peel extract for antibacterial activities

Adsorption performance with field emission scanning electron microscopy of fruit peel induced Silver Nanoparticles in C16H18ClN3S for waste water treatment

There is a growing demand for cost-effective and sustainable technologies for treating wastewater as water consumption increases and conventional technologies become more expensive. Nanoparticles have a great deal of potential for use in the treatment of waste water. Their unique surface area allows them to effectively remove toxic metal ions, pathogenic microorganisms, organic and inorganic solutes from water. This study investigated the potential of orange and banana peels as renewable nano adsorbents for removing dyes and dissolved organic compounds from textile wastewater. Orange and banana peels are an optimal selection due to their favourable chemical characteristics, namely the presence of cellulose, pectic, hemicellulose, and lignin. Their capacity to adsorb diverse anionic and cationic compounds on their surface-active sites is attributed to their unique functional group compositions. Silver nanoparticles are able to adsorb heavy metals due to their exceptionally low electrical and thermal resistance and surface plasmon resonance. The samples were thoroughly characterised using field emission scanning electron microscopy (FESEM), UV-Visible spectrometry, Fourier transform infrared spectroscopy (FTIR) and XRD. The nanoparticles were prepared (10 gm,50 gm,100 gm) and subsequently introduced to the wastewater sample. The optical density values were recorded at various time points. The optical density values demonstrate a decline over the course of the experiment, with a notable decrease observed over time. The results of this study provide valuable insights into the efficacy of these natural adsorbents and their potential for sustainable water purification technologies. For the purpose of this research, high performance instrumentation methods were performed as follows:•Field emission scanning electron microscopy for surface morphology studies.•Gas chromatography-mass spectrometry (GC-MS) for analytical technique that combines gas chromatography (GC) and mass spectrometry (MS) to identify unknown substances or contaminants.•Optical density values were measured for different timings of degradation.

Green Synthesis of Zinc Oxide Nanoparticles Using Dillenia Indica and Mikania Micrantha Leaf Extracts: Applications in Photocatalysis and Antibacterial Activity

Researchers are keenly interested in developing metal-based nanoparticles using plant sources as they are eco-friendly, less expensive and simpler. Zinc oxide nanoparticles, symbolized as D-ZnONPs and M-ZnONPs were synthesized in this study utilizing the leaves of D. indica and M. micrantha, respectively, and studied their impact on the growth inhibition of various bacterial strains and on the photocatalysis. By displaying the distinctive surface plasmon resonance (SPR) band at 373 nm in UV-Vis and bands at 450-480 cm-1 corresponding to Zn-O stretching FTIR spectroscopy imparted the formation of ZnONPs which was further supported by X-ray diffraction analysis by showing the polycrystalline nature and a hexagonal wurtzite structure. The spherical form and average particle size of 30 nm of the produced ZnONPs, as confirmed by electron microscopy, are also confirmed to be crystalline. Under natural sunlight, both ZnONPs demonstrate excellent degradation efficacy about 96-99 % within 100 min towards methylene blue (MB). Furthermore, it is noteworthy that both the synthesized ZnONPs exhibited 55-60 % efficacy with respect to antibiotics in inhibiting the growth of various pathogenic bacterial strains. Overall, ZnONPs can be produced on a large-scale using plant sources and employed them in environmental remediation and cosmetic industries as prominent components.

Biogenic Zinc Oxide Nanoparticles as a Promising Antibacterial Agent: Synthesis and Characterization

Nanotechnology has gained popularity in recent years due to its wide-ranging applications within the scientific community. The three main methods for synthesizing nanoparticles are physical, chemical, and biological. However, the adverse effects associated with physical and chemical methods have led to a growing interest in biological methods. Interestingly, green synthesis using plants has gained prominence in developing new treatments for bacterial infections. Zinc oxide nanoparticles (ZnO NPs) produced using environmentally friendly methods are more biocompatible and have potential applications as antibacterial agents in the biomedical field. As a result, this review discusses the green synthesis of ZnO NPs, factors influencing optimal synthesis, characterization techniques, and the antibacterial activity of some plant-mediated ZnO NPs. It also provides a comprehensive and analytical exploration of ZnO NP biosynthesis, the role of phytochemical compounds as reducing and stabilizing agents, the mechanism of action of their antibacterial properties and further highlights the challenges and prospects in this innovative research area.

Photocatalysis oxidative desulfurization of dibenzothiophene in extremely deep liquid fuels on the Z-scheme catalyst ZnO-CuInS2-ZnS intelligently integrated with carbon quantum dots: performance, mechanism, and stability

In this study, we improved the electrochemical and photocatalytic properties of the ZnO-CuInS2-ZnS (ZCZ) material by integrating with carbon quantum dots (CQD) with particle sizes from 2 to 5 nm. The integration of ZnO-CuInS2-ZnS with carbon quantum dots (ZnO-CuInS2-ZnS/CQD:ZCZ-CQD) enhanced the visible light absorption, significantly reduced the electron-hole recombination rate, and facilitated the electron transfer and separation processes as confirmed by UV-visible diffuse reflectance spectroscopy (UV-vis DRS), photoluminescence (PL), and electrochemical impedance spectroscopy (EIS). The successful integration of ZCZ with carbon quantum dots was confirmed using X-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM) methods. The ZCZ/CQD photocatalyst removed up to 98.32% of DBT after 120 minutes of reaction, maintained over 90% durability after 10 cycles, and retained its structure without any changes. The ZCZ photocatalyst integrated with CQD enhances faster dibenzothiophene (DBT) removal by 4.46, 3.24, 2.53, and 1.72 times compared to ZnO, CuInS2, ZnS, and ZnO-CuInS2-ZnS, respectively. Factors influencing the oxidation process of DBT including the mass of the photocatalyst, initial DBT concentration, stability, and reaction kinetics were studied. Through active species trapping experiments, this study demonstrated that the formation of ˙O2 - and ˙OH radicals determines the reaction rate. The mechanism of photocatalysis on ZCZ-CQD materials and the intermediate products formed in the process of photocatalytic oxidative desulfurization of dibenzothiophene is proposed based on electrochemical measurements and GC-MS results.

Effect of orange fruit peel extract concentration on the synthesis of zinc oxide nanoparticles

In this investigation, the impact of reducing agent concentration on the synthesis of zinc oxide nanoparticles (ZnO NPs) was examined. During the synthesis, an assessment of ionic conductivity was carried out, revealing a significant increase in conductivity prior to the introduction of the reducing agent, followed by a sharp decrease upon its addition. Characterization of the ZnO NPs involved ultraviolet-visible spectroscopy, scanning electron microscopy, Fourier-transform infrared spectroscopy, and, X-ray diffraction analysis. The outcomes suggest that the characteristics of the ZnO NPs are influenced by the concentration of the reducing agent during the synthesis process. Notably, the ZnO NPs synthesized with a higher concentration of reducing agent exhibited a narrower optical band gap and increased surface energy. Furthermore, employing a concentration of 0.5 v/v resulted in the rapid production of NPs with relatively uniform sizes. Conversely, concentrations below 0.5 v/v lead to slow formation, while concentrations exceeding 0.5 v/v yielded non-uniform NPs.

Psidium guajava-mediated green synthesis of Fe-doped ZnO and Co-doped ZnO nanoparticles: a comprehensive study on characterization and biological applications

The efficacy of nanoparticles (NPs) in healthcare applications hinges on their biocidal activity and biocompatibility. This research is dedicated to green-synthesized NPs with potent biocidal properties, aiming for high inhibition rates in bacterial infections and offering a multifunctional application, including potential use in anticancer therapy, in comparison to traditional antibiotics. The present study focuses on synthesis of zinc oxide (ZnO) nanoparticles (NPs), including iron-doped ZnO (GZF) and cobalt-doped ZnO (GZC), using the green co-precipitation method involving Psidium guajava (P. guajava) leaf extract. The physicochemical properties of the synthesized NPs were analyzed using various characterization techniques. The antibacterial and anticancer activity depends on the generation of reactive oxygen species (ROS), particle size, surface area, oxygen vacancy, Zn2+ release, and diffusion ability. The antibacterial activity of the synthesized NPs was tested against various Gram-positive (Streptococcus pneumoniae (S. pneumoniae), Bacillus subtilis (B. subtilis) and Gram-negative (Klebsiella pneumoniae (K. pneumoniae), and Pseudomonas aeruginosa (P. aeruginosa) bacterial strains. The zone of inhibition showed higher activity of GZC (18-20 mm) compared to GZF (16-19 mm) and GZO (11-15 mm) NPs. Moreover, anticancer studies against blood cancer cell line (MOLT-4) showed half-maximal inhibitory concentration of 11.3 μg/mL for GZC compared to GZF and GZO NPs with 12.1 μg/mL and 12.5 μg/mL, respectively. Cytotoxicity assessments carried out on the fibroblast L929 cell line indicated that GZO, GZF, and GZC NPs demonstrated cell viabilities of 85.43%, 86.66%, and 88.14%, respectively. Thus, green-synthesized GZC NPs hold promise as multifunctional agents in the biomedical sector.

Sustainable Synthesis of Novel Green-Based Nanoparticles for Therapeutic Interventions and Environmental Remediation

The advancement in nanotechnology has completely revolutionized various fields, including pharmaceutical sciences, and streamlined the potential therapeutic of many diseases that endanger human life. The synthesis of green nanoparticles by biological processes is an aspect of the newly emerging scientific field known as "green nanotechnology". Due to their safe, eco-friendly, nontoxic nature, green synthesis tools are better suited to produce nanoparticles between 1 and 100 nm. Nanoformulation of different types of nanoparticles has been made possible by using green production techniques and commercially feasible novel precursors, such as seed extracts, algae, and fungi, that act as potent reducing, capping, and stabilizing agents. In addition to this, the biofunctionalization of nanoparticles has also broadened its horizon in the field of environmental remediation and various novel therapeutic innovations including wound healing, antimicrobial, anticancer, and nano biosensing. However, the major challenge pertaining to green nanotechnology is the agglomeration of nanoparticles that may alter the surface topology, which can affect biological physiology, thereby contributing to system toxicity. Therefore, a thorough grasp of nanoparticle toxicity and biocompatibility is required to harness the applications of nanotechnology in therapeutics.

A Review of Plant-Mediated ZnO Nanoparticles for Photodegradation and Antibacterial Applications

This review focuses on the synthesis of plant-mediated zinc oxide nanoparticles (ZnO NPs) and their applications for antibacterial and photocatalytic degradation of dyes, thereby addressing the need for sustainable and eco-friendly methods for the preparation of NPs. Driven by the significant rise in antibiotic resistance and environmental pollution from dye pollution, there is a need for more effective antibacterial agents and photocatalysts. Therefore, this review explores the synthesis of plant-mediated ZnO NPs, and the influence of reaction parameters such as pH, annealing temperature, plant extract concentration, etc. Additionally, it also looks at the application of plant-mediated ZnO NPs for antibacterial and photodegradation of dyes, focusing on the influence of the properties of the plant-mediated ZnO NPs such as size, shape, and bandgap on the antibacterial and photocatalytic activity. The findings suggest that properties such as shape and size are influenced by reaction parameters and these properties also influence the antibacterial and photocatalytic activity of plant-mediated ZnO NPs. This review concludes that plant-mediated ZnO NPs have the potential to advance green and sustainable materials in antibacterial and photocatalysis applications.

Harnessing biological synthesis: Zinc oxide nanoparticles for plant biotic stress management

Crop growth and yield are negatively impacted by increased biotic stress in the agricultural sector due to increasing global warming and changing climatic patterns. The host plant's machinery is exploited by biotic stress, which is caused by organisms like bacteria, fungi, viruses, insects, nematodes, and mites. This results in nutrient deprivation, increased reactive oxygen species and disturbances in physiological, morphological, and molecular processes. Although used widely, conventional disease management strategies like breeding, intercropping, and chemical fertilizers have drawbacks in terms of time commitment and environmental impact. An environmentally beneficial substitute is offered by the developing field of nanotechnology, where nanoparticles such as zinc oxide are gaining popularity due to their potential applications as antimicrobials and nano-fertilizers. This review delves into the biological synthesis of ZnO nanoparticles employing plants and microbes, function of ZnO nanoparticles in biotic stress mitigation, elucidating their effectiveness and toxicological implications in agricultural. This study supports a cautious approach, stressing the prudent application of ZnO nanoparticles to avoid possible toxicity, in line with the larger global agenda to end hunger, guarantee food security, and advance sustainable agriculture.

Green synthesis of zinc oxide nanoparticles (ZnO-NPs) by Streptomyces baarnensis and its active metabolite (Ka): a promising combination against multidrug-resistant ESKAPE pathogens and cytotoxicity

Various eco-friendly techniques are being researched for synthesizing ZnO-NPs, known for their bioactivity. This study aimed at biosynthesizing ZnO-NPs using Streptomyces baarnensis MH-133, characterizing their physicochemical properties, investigating antibacterial activity, and enhancement of their efficacy by combining them with a water-insoluble active compound (Ka) in a nanoemulsion form. Ka is a pure compound of 9-Ethyl-1,4,6,9,10-pentahydroxy-7,8,9,10-tetrahydrotetracene-5,12-dione obtained previously from our strain of Streptomyces baarnensis MH-133. Biosynthesized ZnO-NPs employing Streptomyces baarnensis MH-133 filtrate and zinc sulfate (ZnSO4.7H2O) as a precursor were purified and characterized by physicochemical investigation. High-resolution-transmission electron microscopy (HR-TEM) verified the effective biosynthesis of ZnO-NPs (size < 12 nm), whereas dynamic light scattering (DLS) analysis showed an average size of 17.5 nm. X-ray diffraction (XRD) exhibited characteristic diffraction patterns that confirmed crystalline structure. ZnO-NPs efficiently inhibited both Gram-positive and Gram-negative bacteria (MICs: 31.25-125 µg/ml). The pure compound (Ka) was combined with ZnO-NPs to improve effectiveness and reduce dose using checkerboard microdilution. Niteen treatments of Ka and ZnO-NPs combinations obtained by checkerboard matrix inhibited Klebsiella pneumonia. Eleven combinations had fractional inhibitory concentration index (FICi) between 1.03 and 2, meaning indifferent, another five combinations resulted from additive FICi (0.625-1) and only one combination with FICi of 0.5, indicating synergy. In the case of methicillin-resistant S. aureus (MRSA), Ka-ZnO-NPs combinations yielded 23 treatments with varying degrees of interaction. The results showed eleven treatments with indifferent interaction, eight additive interactions, and two synergies with FICi of 0.5 and 0.375. The combinations that exhibited synergy action were transformed into a nanoemulsion form to improve their solubility and bioavailability. The HR-TEM analysis of the nanoemulsion revealed spherical oil particles with a granulated core smaller than 200 nm and no signs of aggregation. Effective dispersion was confirmed by DLS analysis which indicated that Ka-ZnO-NPs nanoemulsion droplets have an average size of 53.1 nm and a polydispersity index (PI) of 0.523. The killing kinetic assay assessed the viability of methicillin-resistant Staphylococcus aureus (MRSA) and K. pneumonia post-treatment with Ka-ZnO-NPs combinations either in non-formulated or nanoemulsion form. Results showed Ka-ZnO-NPs combinations show concentration and time-dependent manner, with higher efficacy in nanoemulsion form. The findings indicated that Ka-ZnO-NPs without formulation at MIC values killed K. pneumonia after 24 h but not MRSA. Our nanoemulsion loaded with the previously mentioned combinations at MIC value showed bactericidal effect at MIC concentration of Ka-ZnO-NPs combination after 12 and 18 h of incubation against MRSA and K. pneumonia, respectively, compared to free combinations. At half MIC value, nanoemulsion increased the activity of the combinations to cause a bacteriostatic effect on MRSA and K. pneumonia after 24 h of incubation. The free combination showed a bacteriostatic impact for 6 h before the bacteria regrew to increase log10 colony forming unit (CFU)/ml over the initial level. Similarly, the cytotoxicity study revealed that the combination in nanoemulsion form decreased the cytotoxicity against kidney epithelial cells of the African green monkey (VERO) cell line. The IC50 for Ka-ZnO-NPs non-formulated treatment was 8.17/1.69 (µg/µg)/ml, but in nano-emulsion, it was 22.94 + 4.77 (µg/µg)/mL. In conclusion, efficient Ka-ZnO-NPs nanoemulsion may be a promising solution for the fighting of ESKAPE pathogenic bacteria according to antibacterial activity and low toxicity.

Sustainable fabrication of dimorphic plant derived ZnO nanoparticles and exploration of their biomedical and environmental potentialities

Although, different plant species were utilized for the fabrication of polymorphic, hexagonal, spherical, and nanoflower ZnO NPs with various diameters, few studies succeeded in synthesizing small diameter ZnO nanorods from plant extract at ambient temperature. This work sought to pioneer the ZnO NPs fabrication from the aqueous extract of a Mediterranean salt marsh plant species Limoniastrum monopetalum (L.) Boiss. and assess the role of temperature in the fabrication process. Various techniques have been used to evaluate the quality and physicochemical characteristics of ZnO NPs. Ultraviolet-visible spectroscopy (UV-VIS) was used as the primary test for formation confirmation. TEM analysis confirmed the formation of two different shapes of ZnO NPs, nano-rods and near hexagonal NPs at varying reaction temperatures. The nano-rods were about 25.3 and 297.9 nm in diameter and in length, respectively while hexagonal NPs were about 29.3 nm. The UV-VIS absorption spectra of the two forms of ZnO NPs produced were 370 and 365 nm for nano-rods and hexagonal NPs, respectively. FT-IR analysis showed Zn-O stretching at 642 cm-1 and XRD confirmed the crystalline structure of the produced ZnO NPs. Thermogravimetric analysis; TGA was also used to confirm the thermal stability of ZnO NPs. The anti-tumor activities of the two prepared ZnO NPs forms were investigated by the MTT assay, which revealed an effective dose-dependent cytotoxic effect on A-431 cell lines. Both forms displayed considerable antioxidant potential, particularly the rod-shaped ZnO NPs, with an IC50 of 148.43 µg mL-1. The rod-shaped ZnO NPs were superior candidates for destroying skin cancer, with IC50 of 93.88 ± 1 µg mL-1 ZnO NPs. Thus, rod-shaped ZnO NPs are promising, highly biocompatible candidate for biological and biomedical applications. Furthermore, both shapes of phyto-synthesized NPs demonstrated effective antimicrobial activity against various pathogens. The outcomes highlight the potential of phyto-synthesized ZnO NPs as an eco-friendly alternative for water and wastewater disinfection.

Amelioration of phytotoxic impact of biosynthesized zinc oxide nanoparticles: Plant growth promoting rhizobacteria facilitates the growth and biochemical responses of Eggplant (Solanum melongena) under nanoparticles stress

The consistently increasing use of zinc oxide nanoparticles (ZnONPs) in crop optimization practices and their persistence in agro-environment necessitate expounding their influence on sustainable agro-environment. Attempts have been made to understand nanoparticle-plant beneficial bacteria (PBB)- plant interactions; the knowledge of toxic impact of nanomaterials on soil-PBB-vegetable systems and alleviating nanotoxicity using PBB is scarce and inconsistent. This study aims at bio-fabrication of ZnONPs from Rosa indica petal extracts and investigates the impact of PBB on growth and biochemical responses of biofertilized eggplants exposed to phyto-synthesized nano-ZnO. Microscopic and spectroscopic techniques revealed nanostructure, triangular shape, size 32.5 nm, and different functional groups of ZnONPs and petal extracts. Inoculation of Pseudomonas fluorescens and Azotobacter chroococcum improved germination efficiency by 22% and 18% and vegetative growth of eggplants by 14% and 15% under NPs stress. Bio-inoculation enhanced total chlorophyll content by 36% and 14 %, increasing further with higher ZnONP concentrations. Superoxide dismutase and catalase activity in nano-ZnO and P. fluorescens inoculated eggplant shoots reduced by 15-23% and 9-11%. Moreover, in situ experiment unveiled distortion and accumulation of NPs in roots revealed by scanning electron microscope and confocal laser microscope. The present study highlights the phytotoxicity of biosynthesized ZnONPs to eggplants and demonstrates that PBB improved agronomic traits of eggplants while declining phytochemicals and antioxidant levels. These findings suggest that P. fluorescens and A. chroococcum, with NPs ameliorative activity, can be cost-effective and environment-friendly strategy for alleviating NPs toxicity and promoting eggplant production under abiotic stress, fulfilling vegetable demands.

Bacteriophages and Green Synthesized Zinc Oxide Nanoparticles in Combination Are Efficient against Biofilm Formation of Pseudomonas aeruginosa

Bacteriophages (phages) are viruses that infect the bacteria within which their reproduction cycle takes place, a process that ends in the lysis and death of the bacterial cell. Some phages are also able to destroy bacterial biofilms. Due to increased antibiotics resistance, Pseudomonas aeruginosa, another biofilm-forming pathogen, is a problem in many parts of the world. Zinc oxide (ZnO) and other metal nanoparticles (NPs) are biologically active and also possess anti-biofilm properties. ZnO-NPs were prepared by the green synthesis method using orange peels. The vibrational peaks of the ZnO-NPs were analyzed using FTIR analysis, and their size and morphological properties were determined using scanning electron microscopy (SEM). The ability of the ZnO-NPs to reduce or eliminate P. aeruginosa biofilm alone or in combination with phages PB10 and PA19 was investigated. The P. aeruginosa cells were effectively killed in the preformed 48 h biofilms during a 24 h incubation with the ZnO-NP-phage combination, in comparison with the control or ZnO-NPs alone. The treatments on growing biofilms were most efficient in the final stages of biofilm development. All five treatment groups showed a significant biofilm reduction compared to the control group (p < 0.0001) at 48 h of incubation. The influence of the ZnO-NPs and phages on the quorum sensing system of P. aeruginosa was monitored by quantitative real-time PCR (qRT-PCR) of the autoinducer biosynthesis gene lasI. While the ZnO-NPs repressed the lasI gene transcription, the phages slightly activated it at 24 and 48 h of incubation. Also, the effect of the ZnO-NPs and phage PA19 on the viability of HFF2 cells was investigated and the results showed that the combination of NPs with PA19 reduced the toxic effect of ZnO-NPs and also stimulated the growth in normal cells.

Molecular Docking Approach for Biological Interaction of Green Synthesized Nanoparticles

In recent years, significant progress has been made in the subject of nanotechnology, with a range of methods developed to synthesize precise-sized and shaped nanoparticles according to particular requirements. Often, the nanoparticles are created by employing dangerous reducing chemicals to reduce metal ions into uncharged nanoparticles. Green synthesis or biological approaches have been used recently to circumvent this issue because biological techniques are simple, inexpensive, safe, clean, and extremely productive. Nowadays, much research is being conducted on how different kinds of nanoparticles connect to proteins and nucleic acids using molecular docking models. Therefore, this review discusses the most recent advancements in molecular docking capacity to predict the interactions between various nanoparticles (NPs), such as ZnO, CuO, Ag, Au, and Fe3O4, and biological macromolecules.

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.

Central composite design and mechanism of antibiotic ciprofloxacin photodegradation under visible light by green hydrothermal synthesized cobalt-doped zinc oxide nanoparticles

In this research, different Co2+ doped ZnO nanoparticles (NPs) were hydrothermally synthesized by an environmentally friendly, sustainable technique using the extract of P. capillacea for the first time. Co-ZnO was characterized and confirmed by FTIR, XPS, XRD, BET, EDX, SEM, TEM, DRS UV-Vis spectroscopy, and TGA analyses. Dislocation density, micro strains, lattice parameters and volume of the unit cell were measured using XRD results. XRD suggests that the average size of these NPs was between 44.49 and 65.69 nm with a hexagonal wurtzite structure. Tauc plot displayed that the optical energy bandgap of ZnO NPs (3.18) slowly declines with Co doping (2.96 eV). Near complete removal of the ciprofloxacin (CIPF) antibiotic was attained using Green 5% of Hy-Co-ZnO in the existence of visible LED light which exhibited maximum degradation efficiency (99%) within 120 min for 30 ppm CIPF initial concentration. The photodegradation mechanism of CIPF using Green Hy-Co-ZnO NPs followed the Pseudo-first-order kinetics. The Green Hy-Co-ZnO NPs improved photocatalytic performance toward CIPF for 3 cycles. The experiments were designed using the RSM (CCD) method for selected parameters such as catalyst dosage, antibiotic dosage, shaking speed, and pH. The maximal CIPF degradation efficiency (96.4%) was achieved under optimum conditions of 39.45 ppm CIPF dosage, 60.56 mg catalyst dosage, 177.33 rpm shaking speed and pH 7.57.

Metal-Based Nanomaterials for the Sensing of NSAIDS

Cadmium sulfide and zinc oxide nanoparticles were prepared, characterized and used as electrode modifiers for the sensing of two non-steroidal anti-inflammatory drugs (NSAIDs): naproxen and mobic. The structural and morphological characterization of the synthesized nanoparticles was carried out by XRD, UV-Vis spectroscopy, FTIR and scanning electron microscopy. The electrode's enhanced surface area facilitated the signal amplification of the selected NSAIDs. The CdS-modified glassy carbon electrode (GCE) enhanced the electro-oxidation signals of naproxen to four times that of the bare GCE, while the ZnO-modified GCE led to a two-fold enhancement in the electro-oxidation signals of mobic. The oxidation of both NSAIDs occurred in a pH-dependent manner, suggesting the involvement of protons in their electron transfer reactions. The experimental conditions for the sensing of naproxen and mobic were optimized and, under optimized conditions, the modified electrode surface demonstrated the qualities of sensitivity and selectivity, and a fast responsiveness to the target NSAIDs.

Recent advancements in sustainable synthesis of zinc oxide nanoparticles using various plant extracts for environmental remediation

The sustainable synthesis of zinc oxide nanoparticles (ZnO-NPs) using plant extracts has gained significant attention in recent years due to its eco-friendly nature and potential applications in numerous fields. This synthetic approach reduces the reliance on non-renewable resources and eliminates the need for hazardous chemicals, minimizing environmental pollution and human health risks. These ZnO-NPs can be used in environmental remediation applications, such as wastewater treatment or soil remediation, effectively removing pollutants and improving overall ecosystem health. These NPs possess a high surface area and band gap of 3.2 eV, can produce both OH° (hydroxide) and O2-° (superoxide) radicals for the generation of holes (h+) and electrons (e-), resulting in oxidation and reduction of the pollutants in their valence band (VB) and conduction band (CB) resulting in degradation of dyes (95-100% degradation of MB, MO, and RhB dyes), reduction and removal of heavy metal ions (Cu2+, Pb2+, Cr6+, etc.), degradation of pharmaceutical compounds (paracetamol, urea, fluoroquinolone (ciprofloxacin)) using photocatalysis. Here, we review an overview of various plant extracts used for the green synthesis of ZnO NPs and their potential applications in environmental remediation including photocatalysis, adsorption, and heavy metal remediation. This review summarizes the most recent studies and further research perspectives to explore their applications in various fields.

Exploring the potential of a Ephedra alata leaf extract: Phytochemical analysis, antioxidant activity, antibacterial properties, and green synthesis of ZnO nanoparticles for photocatalytic degradation of methylene blue

Ephedra alata leaf extracts have therapeutic properties and contain various natural compounds known as phytochemicals. This study assessed the phytochemical content and antioxidant effects of a Ephedra alata leaf extract, as well as zinc oxide (ZnO) nanoparticle production. The extract contained phenolic acids, including vanillic acid, chlorogenic acid, gallic acid, p-coumaric acid, vanillin and rutin. Its total phenolic content and total flavonoid content were 48.7 ± 0.9 mg.g-1 and 1.7 ± 0.4 mg.g-1, respectively. The extract displayed a DPPH inhibition rate of 70.5%, total antioxidant activity of 49.5 ± 3.4 mg.g-1, and significant antimicrobial activity toward Gram-positive and negative bacteria. The synthesized ZnO nanoparticles had spherical shape, crystallite size of 25 nm, particle size between 5 and 30 nm, and bandgap energy of 3.3 eV. In specific conditions (90 min contact time, pH 7, and 25°C), these nanoparticles efficiently photodegraded 87% of methylene blue, suggesting potential applications for sustainable water treatment and pollution control.

Investigating the effect of acidic and basic precipitation on the antibacterial activity of ZnO nanoparticles against Gram-negative and Gram-positive bacteria

In the present work, acidic (direct) and basic precipitation (indirect) methods were used to demonstrate the influence of the mode of precipitation on the structural properties of ZnO nanoparticles (NPs). Four samples of ZnO nanoparticles were prepared, two samples via each mode of precipitation. DZOa and IZOa were the aged samples prepared via acidic and basic precipitation methods, and DZOwa and IZOwa were processed without aging. Both precipitation processes were carried out without using any surfactant reagents. Zinc hydroxide precipitate, which was formed during the basic precipitation method, could be critical in deciding the properties of ZnO NPs, unlike zinc hydroxide formed during acidic precipitation. Aging of zinc hydroxide, synthesised by basic precipitation method for 48 hours was found to be an added advantage in controlling the properties of ZnO NPs. The influence of the mode of precipitation on the structural properties and antibacterial activity of ZnO NPs against Gram-positive and Gram-negative bacterial strains was tested. The antibacterial activity of all four ZnO NPs was analysed via zone of inhibition measurements at a concentration dose of 200 μg ml-1. IZOa nanoparticles prepared using the basic precipitation method showed a higher antibacterial activity against three Gram-negative and one Gram-positive strains, namely, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. DZOa nanoparticles synthesized through acidic precipitation showed relatively high antibacterial activity against Salmonella typhimurium, a Gram-negative strain. ZnO NPs prepared without aging, IZOwa and DZOwa, showed a higher antibacterial activity against E. coli and Bacillus sp. strains, respectively. All ZnO NPs were characterized via UV-visible, FTIR, XRD, and HRSEM techniques.

Green synthesis of zinc oxide nano particles using Allium cepa L. waste peel extracts and its antioxidant and antibacterial activities

Synthesis of nanoparticles through the green approach using plant and vegetable extracts has gained popularity since they are thought to be efficient and cost-effective materials. This study is designed to synthesize zinc oxide nanoparticles (ZnO-NPs) from onion waste peel extract (Allium cepa L.) via the green synthesis approach. The synthesized ZnO-NPs were characterized by utilizing the UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), Energy Dispersive X-ray (EDX), Field Emission Scanning Electron Microscopy (FE-SEM) and X-ray Powder Diffraction (XRD)techniques. The nanoparticles formation was confirmed by the UV-Vis sharp absorption spectra at 318 and 322 nm. The synthesized ZnO-NPs size and shape was revealed by the XRD and SEM respectively. Smallest nanoparticle average crystallite size was found 57.38 nm with hexagonal shape. The bioactive functional groups that are in charge of capping and stabilizing the ZnO-NPs was assured by the FTIR data. Further, prepared ZnO-NPs were used to assess their possible antioxidant and antibacterial properties. DPPH test for free radical scavenging showed potential antioxidant properties of the synthesized ZnO-NPs. The antibacterial activity were studied against three clinical strains: P. aeruginosa, E. coli, and S. aureus with the maximum zone of inhibition 13.17 mm, 22.00 mm and 12.35 mm respectively at 100 μg/mL subsequently minimum inhibitory concentration was found 50 μg/mL for P. aeruginosa, and S. aureus whereas 100 μg/mL for E. coli. Antioxidant and antibacterial activity tests appear bio-resource based ZnO-NPs from Allium cepa L. extract have effects on free radical and growth of microorganisms.Therefore, it could be a promising candidates for agricultural and food safety applications as an effective antimicrobial agent against pathogenic microorganisms and also can address future biomedical applications after complete in vivo study.

Aloe vera assisted green synthesis of Ag and Cu co-doped ZnO nanoparticles and a comprehensive analysis of their structural, morphological, optical, electrical and antibacterial properties

This study investigates the potential of utilizing Aloe vera-assisted green synthesis with transition metal dopants of Ag and Cu for greater efficiency and sustainability in advanced scientific applications utilizing ZnO nanoparticles. Samples were prepared using the co-precipitation method, maintaining a basic pH media of 10. Aloe vera gel extract was chosen for its acclaimed role as a stabilizing and reducing agent and its proven antioxidant, antibacterial, and anticancer properties. The XRD report revealed the hexagonal Wurtzite crystal structure of nanoparticles, exhibiting a crystallite size range of 17-23 nm with substantial alterations in lattice parameters, dislocation density, and bond lengths when dopants were added. Additionally, EDX analysis confirmed the perfect doping of Ag and Cu in ZnO without any impurities. SEM analysis indicated a reduction in agglomeration, accompanied by a transition in particle morphology from columnar to globular. Additionally, the optical study showed a band gap range of 3.18-3.27 eV, confirming it to be a wide band gap semiconductor. The effect of dopants resulted in an increase in transparency and band gap, while a decrease in absorption coefficient in the visible wavelength region. With increasing temperature, a decline in electrical resistivity was noted, with co-doped nanoparticles consistently exhibiting the lowest resistivity, affirming semiconductor characteristics. Most importantly, A remarkable antibacterial efficacy was noticed at low concentrations against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria. The zone of inhibition produced by nanoparticles exhibited values akin to the antibiotic control, even at substantially lower doses. This research offers a comprehensive analysis of the effects of Ag and Cu in Aloe vera-assisted green-synthesized ZnO nanoparticles, concurrently addressing their potential applications in biomedical, energy storage, and optoelectronic devices.

Biosynthesis of silver nanoparticles by banana pulp extract: Characterizations, antibacterial activity, and bioelectricity generation

Here, green banana pulp extract (PE) has been used as a bio-reducing agent for the reduction of silver ions to silver nanoparticles (AgNPs). Bio-synthesized AgNPs were characterized by using UV, XRD, FEEM, TEM, and FTIR analysis. The face-centered cubic structures of AgNPs were formed with an average crystallite size of 31.26 nm and an average particle size of 42.97 nm. In this report, the electrical activities of green synthesized AgNPs have been evaluated along with the antibacterial activities. The antibacterial activities of AgNPs were evaluated against two pathogenic bacteria: Escherichia coli (gram-negative) and Staphylococcus epidermidis (gram-positive). AgNPs were added to the electrochemical cell and results demonstrated the improvement of power of the electrochemical cell. Green synthesized AgNPs showed excellent antibacterial activities against both gram-positive and negative bacteria and most importantly the NPs played an important role as an effective catalyst to enhance the electrical performance of bio-electrochemical cells. These significant findings may help in the advancement of nanotechnology in biomedical applications as well as in the creation of cheap and eco-friendly power generation devices.

Development of new generation cakes fortified with zinc oxide nanoparticles

This study aimed to develop new generation cakes that were fortified with calcined ZnO nanoparticles (CZnO), uncalcined ZnO nanoparticles (UCZnO), beads (B(CZnO)) synthesized by encapsulating the CZnO with sodium alginate (SA), and the beads (B(UCZnO)) synthesized by encapsulating the UCZnO with sodium alginate (SA) and investigated the zinc (Zn) release in fortified cakes in simulated body fluids (SBF). The present study represents a novel method for increasing intestinal absorption and bioavailability of dietary zinc with zinc nanoparticles for use in the preparation of Zn fortified cakes as a dietary supplement to compensate for zinc deficiency in humans. The results revealed that a rapid increase in the release time and rate in the SGF solution was noted in the UCZnO added cakes. It was attributed to increased intestinal absorption and bioavailability as a result of the ultra-small size of ZnO. Also, ZnO release kinetics in SBF was also studied and data were adjusted into different kinetic models involving zero-order, first-order, Higuchi, and Korsmeyer-Peppas models. The present investigation recommends adding UCZnO to the cakes to control and increase the release from the cakes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05840-x.

Green synthesis of ZnO nanoparticles from ball moss (Tillandsia recurvata) extracts: characterization and evaluation of their photocatalytic activity

Green synthesis (GS), referred to the synthesis using bioactive agents such as plant materials, microorganisms, and various biowastes, prioritizing environmental sustainability, has become increasingly relevant in international scientific practice. The availability of plant resources expands the scope of new exploration opportunities, including the evaluation of new sources of organic extracts, for instance, to the best of our knowledge, no scientific articles have reported the synthesis of zinc oxide nanoparticles (ZnO NPs) from organic extracts of T. recurvata, a parasitic plant very common in semiarid regions of Mexico.This paper presents a greener and more efficient method for synthesizing ZnO NPs using T. recurvata extract as a reducing agent. The nanoparticles were examined by different techniques such as UV-vis spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and BET surface analysis. The photocatalytic and adsorptive effect of ZnO NPs was investigated against methylene blue (MB) dye in aqueous media under sunlight irradiation considering an equilibrium time under dark conditions. ZnO nanoparticles were highly effective in removing MB under sunlight irradiation conditions, showing low toxicity towards human epithelial cells, making them promising candidates for a variety of applications. This attribute fosters the use of green synthesis techniques for addressing environmental issues.This study also includes the estimation of the supported electric field distributions of ZnO NPs in their individual spherical or rounded shapes and their randomly oriented organization, considering different diameters, by simulating their behavior in the visible wavelength range, observing resonant enhancements due to the strong light-matter interaction around the ZnO NPs boundaries.

Hydrothermal fabrication, characterization and RSM optimization of cobalt-doped zinc oxide nanoparticles for antibiotic photodegradation under visible light

Photodegradation is considered a significant method engaged for the elimination of organic pollutants from water. In this work, hydrothermal cobalt-doped zinc oxide nanoparticles (Hy-Co-ZnO NPs) loaded with 5, 10, and 15% cobalt were prepared in a hydrothermal way and were investigated as a photocatalyst for the Ciprofloxacin (CIPF) degradation under visible irradiation using LED-light. Characterization approaches such as FTIR, XRD, XPS, DRS UV-vis spectroscopy, SEM, TEM, BET, EDX and TGA were used for the investigation of the fabricated Hy-Co-ZnO NPs. The studies indicated that 10% Hy-Co-ZnO NPs was the most efficient catalyst for the CIPF photolysis compared to ZnO NPs and other Hy-Co-ZnO NPs with 5 and 15% cobalt content. Higher photocatalytic activity (> 98%) of 20 mg/L of CIPF solution was attained within 60 min. The reaction kinetics showed that the first-order model is suitable for displaying the rate of reaction and amount of CIPF elimination with R2 = 0.9883. Moreover, Central composite design (CCD) optimization of the 10% Hy-Co-ZnO NPs was also studied.

The physical properties and photocatalytic activities of green synthesized ZnO nanostructures using different ginger extract concentrations

The green synthesis method which is aligned with the sustainable development goals (SDGs) theory, is proposed to synthesize ZnO nanoparticles using ginger extract to treat the acidic wastewater and acidic factory effluent as a current challenge and the effects of the concentration of extracts on the synthesized ZnO nanostructures are investigated. The results declare that the single-phase hexagonal ZnO is formed using ginger extract concentration of less than 25 mL and the crystallite size of green synthesized ZnO NPs increased with increasing the concentration of ginger extract. Also, the significant effects of ginger extract concentration on the morphology of nanoparticles (nanocone, nanoflakes, and flower-like) and the particle size are demonstrated. The low concentration of ginger extract leads to the formation of the ZnO nanoflakes, while the flower-like structure is gradually completed by increasing the concentration of the ginger extract. Furthermore, significant changes in the specific surface area (SSA) of the samples are observed (in the range of 6.1-27.7 m2/g) by the variation of ginger extract concentration and the best SSA is related to using 10 mL ginger extract. Also, the strong effect of using ginger extract on the reflectance spectra of the green synthesized ZnO NPs, especially in the UV region is proved. The indirect (direct) band gap energies of the ZnO samples are obtained in the range of 3.09-3.20 eV (3.32-3.38 eV). Furthermore, the photocatalytic activities of the samples for the degradation of methylene blue indicate the impressive effect of ginger extract concentration on the degradation efficiency of ZnO nanoparticles and it reaches up to 44% and 83% for ZnO NPs prepared using 5 mL ginger extract in a pH of 4.3 and 5.6, respectively. This study provided new insights into the fabrication and practical application of high-performance ZnO photocatalysts synthesized using ginger extract in degrading organic pollutants in an acidic solution.

Photocatalytic and Antimicrobial Properties of ZnO and Mg-Doped ZnO Nanoparticles Synthesized Using Lupinus albus Leaf Extract

Dye effluents discharged from various industries contribute to environmental contamination, making their treatment highly necessary. Infectious diseases also pose a threat to public health worldwide. Nanomaterials have promising features and are potential candidates for overcoming the problems of drug resistance in microbes and environmental pollution. Therefore, this study aimed to synthesize zinc oxide (ZnO) and magnesium-doped zinc oxide (Mg-doped ZnO) nanoparticles (NPs) using the plant extract of Lupinus albus for applications in photocatalysis and antimicrobial activity. A sample of Lupinus albus leaves was collected from Motta, in the eastern Gojjam zone of Ethiopia. The leaves were air-dried and then ground into a powder. The powdered plant material was extracted using distilled water. The ZnO and Mg-doped ZnO NPs were synthesized using 0.1 M Zn(NO3)2·6H2O, 7.5% 0.1 M Mg(NO3)2.6H2O, and 10 mL of the leaf extract. The nanoparticles (NPs) were characterized using UV-vis, FT-IR, XRD, and SEM. The average crystallite sizes of ZnO and Mg-doped ZnO NPs were determined using the Debye-Scherrer formula and were found to be 28.1 and 34.4 nm, respectively. The antimicrobial activity of the synthesized NPs was evaluated against four bacterial strains (Escherichia coli, Bacillus cereus, Salmonella typhi, and Staphylococcus aureus) and one fungal strain (Candida albicans) by using the agar disk diffusion method. The Mg-doped ZnO NPs exhibited significant antimicrobial activity, with a maximum zone of inhibition measuring 24 and 22 mm against Escherichia coli and Salmonella typhi, respectively. The photocatalytic activity of ZnO and Mg-doped ZnO NPs was investigated by studying the degradation of methylene blue (MB) dye under sunlight irradiation for 120 min. The results showed that Mg-doped ZnO NPs exhibited higher photocatalytic activity (99.6%) than ZnO NPs (94.1%). In conclusion, the synthesized NPs could serve as viable alternatives for antimicrobial drugs and photocatalysts to mitigate the pollution of the environment caused by organic dyes.

Marine-derived κ-carrageenan-coated zinc oxide nanoparticles for targeted drug delivery and apoptosis induction in oral cancer

BACKGROUND

Kappaphycus alvarezii, a marine red algae species, has gained significant attention in recent years due to its versatile bioactive compounds. Among these, κ-carrageenan (CR), a sulfated polysaccharide, exhibits remarkable antimicrobial properties. This study emphasizes the synergism attained by functionalizing zinc oxide nanoparticles (ZnO NPs) with CR, thereby enhancing its antimicrobial efficacy and target specificity against dental pathogens.

METHODS

In this study, we synthesized ZnO-CR NPs and characterized them using SEM, FTIR, and XRD techniques to authenticate their composition and structural attributes. Moreover, our investigation revealed that ZnO-CR NPs possess better free radical scavenging capabilities, as evidenced by their effective activity in the DPPH and ABTS assay.

RESULTS

The antimicrobial properties of ZnO-CR NPs were systematically assessed using a zone of inhibition assay against dental pathogens of S. aureus, S. mutans, E. faecalis, and C. albicans, demonstrating their substantial inhibitory effects at a minimal concentration of 50 μg/mL. We elucidated the interaction between CR and the receptors of dental pathogens to further understand their mechanism of action. The ZnO-CR NPs demonstrated a dose-dependent anticancer effect at concentrations of 5 μg/mL, 25 μg/mL, 50 μg/mL, and 100 μg/mL on KB cells, a type of Human Oral Epidermal Carcinoma. The mechanism by which ZnO-CA NPs induced apoptosis in KB cells was determined by observing an increase in the expression of the BCL-2, BAX, and P53 genes.

CONCLUSION

Our findings unveil the promising potential of ZnO-CR NPs as a candidate with significant utility in dental applications. The demonstrated biocompatibility, potent antioxidant and antiapoptotic activity, along with impressive antimicrobial efficacy position these NPs as a valuable resource in the ongoing fight against dental pathogens and oral cancer.

Enhancing wheat crop production with eco-friendly chitosan encapsulated nickel oxide nanocomposites: A safe and sustainable solution for higher yield

In this work, we looked at using nickel oxide (NiO) nanocomposites with chitosan encapsulation as a nano-primer to improve wheat crop output. A straightforward green precipitation procedure was used to create the nanocomposites, and they were then characterized using several methods. According to the findings, the chitosan-encapsulated NiO nanocomposites possessed a large surface area and were resilient to changes in pH. Following this, wheat seeds were primed with the nanocomposites, and under greenhouse circumstances, the impact on crop growth was assessed. The findings demonstrated that, in comparison to the control group, nanocomposites priming considerably enhanced wheat growth and germination rate up to 99 %. In comparison to untreated plants, the wheat plants treated with the nanocomposites primer had greater plant height i.e. shoot length (11.4 cm) and root length (10.3 cm), leaf area, and biomass accumulation. Further research into the mechanism underlying the priming effect of nanocomposites on wheat growth revealed that the nanocomposites enhanced nutrient absorption, photosynthesis, and stress tolerance in wheat plants. In conclusion, our research shows that chitosan-encapsulated NiO nanocomposites have the potential to improve wheat crop productivity in an environmentally benign and long-term manner, offering a viable strategy for sustainable farming.

Phase controlled green synthesis of wurtzite (P63mc) ZnO nanoparticles: interplay of green ligands with precursor anions, anisotropy and photocatalysis

Green approaches for nanosynthesis often lack the precise control of synthetic outcomes, which is primarily due to the poorly defined reaction protocols. Herein, we investigated the use of lignocellulosic agro-waste, sugarcane press mud (PM), for the synthesis of ZnO nanoparticles using three different precursor salts and their further application in the photocatalytic degradation of rhodamine dyes. This approach resulted in the formation of ZnO nanoparticles with two different morphologies, i.e., sheet-like structure from the zinc sulphate and nitrate precursors, whereas sphere-like structures from zinc acetate. In all three cases, the wurtzite phase (P63mc) of ZnO nanoparticles remained consistent. Also, the ZnO nanoparticles were found to be positively charged ("ζ" = +8.81 to +9.22 mv) and nearly monodispersed, with a size and band gap in the range of ∼14-20 nm and 3.78-4.1 eV, respectively. Further, the potential photocatalytic activity of these nanoparticles was investigated under direct sunlight. At the same photocatalyst dose of 0.1 g L-1, the three ZnO nanoparticles showed varying efficiencies due to their shape anisotropy. The ZnO NPs from acetate salt (∼20 nm, sheet like) showed the highest dye degradation efficiency (90.03%) in 4.0 hours, indicating the role of the catalyst-dye interface in designing efficient photocatalysts.

Efficacy of ascorbic acid and different sources of orange peel on growth performance, gene expression, anti-oxidant status and microbial activity of growing rabbits under hot conditions

Orange peel and its extract are good sources of phenols and vitamin C that can be used as powerful antioxidants and antibacterial. The effects of dietary ascorbic acid (AA), orange peel powder (OPP) and orange peel extract (OPE) supplementations on growth performance, blood biochemicals, gene expression and antioxidant status of growing rabbits under hot conditions were investigated. A total of 80 weaned Giant Flander male rabbits, five weeks old (606.25 ± 10.08 g), were randomly assigned to four groups. The first group received untreated diet (control group). The other groups received diets supplemented with 0.5 g AA/kg diet, 2% OPP and 500 mg OPE/kg diet. The lowest feed conversion ratio (FCR) was recorded by rabbits consumed diet supplemented with AA. Supplementations of OPP and OPE reduced blood plasma total cholesterol, low density lipoprotein and very-low density lipoprotein concentrations. The tested diets reduced triglycerides, total lipids, hydrogen peroxide, malondialdehyde levels, Staphylococcus aureus and Escherichia coli of the rabbits cecum. Supplementation of OPE improved activities of superoxide dismutase gene (6.1475) and insulin-like growth factor-1 (9.2108). Conclusively, dietary supplementation of OPE improved rabbit performance through improving antioxidant enzyme activities as well as upregulation of insulin-like growth gene. Additionally, OPP and OPE (2% and 500 mg/kg diet, respectively) had antibacterial effects for growing rabbits under hot conditions.

Cube-shaped Cobalt-doped zinc oxide nanoparticles with increased visible-light-driven photocatalytic activity achieved by green co-precipitation synthesis

From the perspective of environmental protection, the highly efficient degradation of antibiotics and organic dyes in wastewater needs to be tackled as soon as possible. In this study, an ecofriendly and green cube-shaped cobalt-doped zinc oxide nanoparticles (Co-ZnO NPs) photocatalyst using Pterocladia Capillacea (P. Capillacea) water extract loaded with 5, 10, and 15% cobalt ions were formed via co-precipitation process to degrade antibiotics. The prepared Co-ZnO NPs were tested as a photocatalyst for the photodegradation of ciprofloxacin (CIPF) in the presence of a visible LED-light source. Co-ZnO NPs have been obtained through the co-precipitation method in the presence of P. Capillacea extract as a green capping agent and reducing agent, for the first time. Several characterization techniques including FTIR, XRD, BET, XPS, TEM, EDX, SEM, TGA and DRS UV-Vis spectroscopy were applied to study the prepared Co-ZnO NPs. XRD results suggested that the average size of these NPs ranged between 42.82 and 46.02 nm with a hexagonal wurtzite structure. Tauc plot shows that the optical energy bandgap of ZnO NPs (3.19 eV) gradually decreases to 2.92 eV by Co doping. Examinations showed that 5% Co-ZnO NPs was the highest efficient catalyst for the CIPF photodegradation when compared with ZnO NPs and other 10 and 15% Co-ZnO NPs. A 10 mg/L solution of CIPF was photo-degraded (100%) within the first 15 min irradiation. The kinetics showed that the first-order model is suitable for displaying the rate of reaction and amount of CIPF elimination with R2 = 0.952. Moreover, central composite design optimization of the 5% Co-doped ZnO NPs was also investigated.

Innovative Preparation of Cellulose-Mediated Silver Nanoparticles for Multipurpose Applications: Experiment and Molecular Docking Studies

In recent years, inorganic metal nanoparticle fabrication by extraction of a different part of the plant has been gaining more importance. In this research, cellulose-mediated Ag nanoparticles (cellulose/Ag NPs) with excellent antibacterial and antioxidant properties and photocatalytic activity have been synthesized by the microwave-assisted hydrothermal method. This method is a green, simple, and low-cost method that does not use any other capping or reducing agents. X-ray diffraction (XRD), Fourier transform infrared (FTIR), field emission scanning microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), and UV-visible spectroscopic techniques were used to investigate the structure, morphology, as well as components of the generated cellulose/Ag NPs. In fact, XRD results confirm the formation of the face-centered cubic phase of Ag nanoparticles, while the FTIR spectra showed that the synergy of carbohydrates and proteins is responsible for the formation of cellulose/Ag NPs by the green method. It was found that the green-synthesized silver nanoparticles showed good crystallinity and a size range of about 20-30 nm. The morphology results showed that cellulose has a cavity-like structure and the green-synthesized Ag NPs were dispersed throughout the cellulose polymer matrix. In comparison to cellulose/Ag NPs and Ag nanoparticles, cellulose/Ag NPs demonstrated excellent antibacterial activity, Proteus mirabilis (MTCC 1771) possessed a maximum inhibition zone of 18.81.5 mm at 2.5 g/mL, and Staphylococcus aureus (MTTC 3615) had a minimum inhibition zone of 11.30.5 mm at 0.5 g/mL. Furthermore, cellulose/Ag NPs also exhibited a significant radical scavenging property against the DDPH free radical, and there was a higher degradation efficiency compared to pure Ag NPs against Rhodamine B as 97.38% removal was achieved. Notably, cellulose/Ag NPs remarkably promoted the transfer and separation of photogenerated electron-hole (e-/h+) pairs, thereby offering prospective application of the photodegradation efficiency for Rhodamine B (RhB) as well as antibacterial applications. With the findings from this study, we could develop efficient and environmentally friendly cellulose/Ag nanoparticles using low-cost, environmentally friendly materials, making them suitable for industrial and technological applications.

Growth and metabolism of pea (Pisum sativum) via biostimulants based on greener ZnO nanoparticles

The purpose of this study was to identify the most important physiological and biological effects of green synthesis ZnO nanoparticles at a size of 65 nm, biostimulant (Folcare) and interaction biostimulant ZnO NPs on plant growth and metabolism. As our understanding of biostimulants' preventive and restorative modes of action has increased, it is critical to maintain the best crop output and quality possible. The reduction of fertilizers must be substituted by strategies that improve the nutrients uptake or their utilization by the plants. New processing methods are required as an efficient green process or an integrated (hybrid) process for different new technologies of interest. The effects of NPs, biostimulant, and combination ZnO NPs biostimulant on plant cell metabolism were examined in cytosol, chloroplast, and mitochondria of cells from the stems, roots, and leaves. The interaction NPs/biostimulant had a beneficial effect on the morphological and physiological indicators of plant health than when nanoparticles and biostimulant are applied separately. Folcare biostimulant coupled with zinc oxide nanoparticles improved pea crops growth. The improved of the quality of pea plants can be explained at least, in part, by increase in antioxidant activities during plant growth phenophase.

Zinc oxide nanorod/rutin modified electrode for the detection of Thiourea in real samples

In this work, a novel electrochemical detection strategy was developed based on a metal-organic framework of zinc oxide nanorod nanoparticles and rutin for selective screening of Thiourea as toxic chemicals. The zinc oxide nanorod were synthesized by following direct chemical precipitation methods and characterized by X-ray diffraction and X-ray photoelectron spectroscopy analysis. The surface of modified electrodes was also characterized by field emission scanning electron microscopes, energy-dispersive X-ray spectroscopy, and attenuated total reflectance flourier transform infrared spectroscopy. Furthermore, the electrochemical activity of the developed sensor was tested by cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy. The modified electrode showed outstanding electro-catalytic activity towards the detection of Thiourea in phosphate buffer saline at a high pH level of 12.0. The proposed sensor showed a linear range of linearity in a concentration ranging from 5.0 × 10-6 - 900 × 10-6 molL-1 and a detection limit of 2.0 × 10-6 molL-1. Moreover, the selectivity of the developed electrochemical sensor was investigated for the detection of Thiourea in the presence of organic compounds and a group of anions. Furthermore, the proposed strategy demonstrated an excellent recovery value in the spiked farmland water and fruit juice sample.

Current scenario on biogenic synthesis of metal oxide nanocomposites using plant specimens and their application towards treatment of wastewater

Various industries such as textile, leather, and paper mills discharge huge amount of industrial effluents to the environment containing unconsumed dyes and toxic heavy metal ions which are very harmful and carcinogenic in nature. The increase in water pollution is adversely impacting the ecosystems and human health. Now, it has become a great challenge to treat the contaminated water/wastewater. Photocatalysis and adsorption are the two techniques gaining significant attention for the removal of toxic pollutants from wastewater effectively. In this regard, metal oxide-based nanomaterials and their composites have gained profound attention in photocatalytic degradation as well as adsorptive removal of toxic pollutants from water due to their chemical reactivity, higher surface area, regeneration efficiency, ample adsorption sites, intriguing photocatalytic activity, and cost-effectiveness. However, the conventional methods, employed to synthesize these metal oxide nanocomposites, involve the use of toxic chemicals which again produce secondary pollutants. Among all biological materials, the use of plant biomolecules is found to be the most effective way to synthesize stable nanomaterials, as the phytoconstituents of plants act as reducing, capping, and stabilizing agent. It is experimentally proved that bio-based nanocomposites have tremendous potential towards the degradation of environmental pollutants. Thus, there is a great need to work on the synthesis of some novel plant-based metal oxide nanocomposites and their applications in the field of water treatment. This review mainly discusses the metal oxide nanocomposites synthesized using plant specimens and their various applications towards treatment of water/wastewater.

Antibacterial Activity of ZnO Nanoparticles in a Staphylococcus-aureus-Infected Galleria mellonella Model Is Tuned by Different Apple-Derived Phytocargos

This research investigates pH changes during the green synthesis of ZnO nanoparticles (NPs) and emphasises its importance in their physicochemical, antibacterial, and biological properties. Varying the synthesis pH from 8 to 12 using "Bravo de Esmolfe" apple extracts neither affected the morphology nor crystallinity of ZnO but impacted NP phytochemical loads. This difference is because alkaline hydrolysis of phytochemicals occurred with increasing pH, resulting in BE-ZnO with distinct phytocargos. To determine the toxicity of BE-ZnO NPs, Galleria mellonella was used as an alternative to non-rodent models. These assays showed no adverse effects on larvae up to a concentration of 200 mg/kg and that NPs excess was relieved by faeces and silk fibres. This was evaluated by utilising fluorescence-lifetime imaging microscopy (FLIM) to track NPs' intrinsic fluorescence. The antibacterial efficacy against Staphylococcus aureus was higher for BE-ZnO12 than for BE-ZnO8; however, a different trend was attained in an in vivo infection model. This result may be related to NPs' residence in larvae haemocytes, modulated by their phytocargos. This research demonstrates, for the first time, the potential of green synthesis to modulate the biosafety and antibacterial activity of NPs in an advanced G. mellonella infection model. These findings support future strategies to overcome antimicrobial resistance by utilizing distinct phytocargos to modulate NPs' action over time.

Biogenic nanoparticles from waste fruit peels: Synthesis, applications, challenges and future perspectives

Nanotechnology is a continually growing field with a wide range of applications from food science to biotechnology and nanobiotechnology. As the current world is grappling with non-biodegradable waste, considered more challenging and expensive to dispose of than biodegradable waste, new technologies are needed today more than ever. Modern technologies, especially nanotechnology, can transform biodegradable waste into products for human use. Researchers are exploring sustainable pathways for nanotechnology by utilizing biodegradable waste as a source for preparing nanomaterials. Over the past ten years, the biogenic production of metallic nanoparticles (NPs) has become a promising alternative technique to traditional NPs synthesis due to its simplicity, eco-friendliness, and biocompatibility in nature. Fruit and vegetable waste (after industrial processing) contain various bioactives (such as flavonoids, phenols, tannins, steroids, triterpenoids, glycosides, anthocyanins, carotenoids, ellagitannins, vitamin C, and essential oils) serving as reducing and capping agents for NP synthesis and they possess antibacterial, antioxidant, and anti-inflammatory properties. This review addresses various sources of biogenic NPs including their synthesis using fruit/vegetable waste, types of biogenic NPs, extraction processes and extracted biomaterials, the pharmacological functionality of NPs, industrial aspects, and future perspectives. In this manner, this review will cover the most recent research on the biogenic synthesis of NPs from fruit/vegetable peels to transform them into therapeutic nanomedicines.

Bioderived Mesoporous Carbon@Tungsten Oxide Nanocomposite as a Drug Carrier Vehicle of Doxorubicin for Potent Cancer Therapy

Scientists have investigated the possibility of employing nanomaterials as drug carriers. These nanomaterials can preserve their content and transport it to the target region in the body. In this investigation, we proposed a simple method for developing distinctive, bioderived nanostructures with mesoporous carbon nanoparticles impregnated with tungsten oxide (WO3). Prior to characterizing and encapsulating WO3 with bioderived mesoporous carbon, the anticancer drug doxorubicin (DOX) was added to the nanoparticles and examined loading and release study. The approaches for both nanoparticle production and characterization are discussed in detail. Colloidal qualities of the nanomaterial can be effectively preserved while also allowing transdermal transportation of nanoparticles into the body by forming them into green, reusable, and porous nanostructures. Although the theories of nanoparticles and bioderived carbon each have been studied separately, the combination presents a new route to applications connected to nanomedicine. Furthermore, this sample was used to study exotic biomedical applications, such as antioxidant, antimicrobial, and anticancer activities. The W-3 sample had lower antioxidant activity (44.01%) than the C@W sample (56.34%), which was the most potent. A high DOX entrapment effectiveness of 97% was eventually achieved by the C@W sample, compared to a pure WO3 entrapment efficiency of 91%. It was observed that the Carbon/WO3 composite (C@W) sample showed more efficacy because the mesoporous carbon composition with WO3 increases the average surface area and surface-active locations.

Optically amended biosynthesized crystalline copper-doped ZnO for enhanced antibacterial activity

The emergence and re-emergence of antibiotic-resistant bacteria is a potential threat to treating infectious diseases. This study employed a nanometer-scale green synthesis using an extract of Solanum incanum leaves to obtain nanoparticles (NPs) and nanocomposites (NCs) possessing antibacterial properties. The FESEM-EDS elemental mapping analysis proved the novelty of the green synthesis approach in synthesizing a copper-doped ZnO NCs with good dopant distribution. The crystallinity and ZnO bandgap were adjusted by extrinsic copper doping in the ZnO lattice. The optical property adjustments from 3.04 to 2.97 eV for indirect Kubelka-Munk functions were confirmed from DRS-UV-vis analysis. The dopant inclusion in the host lattice was also confirmed by the angle shift on the XRD pattern analysis relative to single ZnO. In addition to doping, the XRD pattern analysis also showed the development of CuO crystals. The lattice fringe values from HRTEM analysis confirmed the existence of both CuO and ZnO crystals with local heterojunctions. Doping and heterojunctions have crucial values in charge transfer and visible light harvesting behaviour, as proved by the PL analysis. The synergistic effects of the doped NCs showed greater antibacterial activity against both Gram-positive and Gram-negative bacteria as a result of more ROS generation through the bacteria-cell-catalyst interaction and release of metal ions. The antioxidant potential of the doped NCs was found to be higher than that of single NPs, using the 2,2-diphenyl-1-picrylhydrazyl free radical scavenging assay and is expected to impart protective effects to the host cells by scavenging destructive free radicals. Thus, the overall analysis leads to the conclusion that the potentiality of synthesized materials has a future outlook for biological applications, especially in the development of antimicrobials to combat antibiotic-resistant bacteria and microbes.

Cellulose-Based Metallogels-Part 2: Physico-Chemical Properties and Biological Stability

Metallogels represent a class of composite materials in which a metal can be a part of the gel network as a coordinated ion, act as a cross-linker, or be incorporated as metal nanoparticles in the gel matrix. Cellulose is a natural polymer that has a set of beneficial ecological, economic, and other properties that make it sustainable: wide availability, renewability of raw materials, low-cost, biocompatibility, and biodegradability. That is why metallogels based on cellulose hydrogels and additionally enriched with new properties delivered by metals offer exciting opportunities for advanced biomaterials. Cellulosic metallogels can be either transparent or opaque, which is determined by the nature of the raw materials for the hydrogel and the metal content in the metallogel. They also exhibit a variety of colors depending on the type of metal or its compounds. Due to the introduction of metals, the mechanical strength, thermal stability, and swelling ability of cellulosic materials are improved; however, in certain conditions, metal nanoparticles can deteriorate these characteristics. The embedding of metal into the hydrogel generally does not alter the supramolecular structure of the cellulose matrix, but the crystallinity index changes after decoration with metal particles. Metallogels containing silver (0), gold (0), and Zn(II) reveal antimicrobial and antiviral properties; in some cases, promotion of cell activity and proliferation are reported. The pore system of cellulose-based metallogels allows for a prolonged biocidal effect. Thus, the incorporation of metals into cellulose-based gels introduces unique properties and functionalities of this material.

Biosynthesis and Optimization of ZnO Nanoparticles Using Ocimum lamifolium Leaf Extract for Electrochemical Sensor and Antibacterial Activity

In this study, zinc oxide nanoparticles (ZnO NPs) were synthesized using an aqueous extract of the Ocimum lamifolium (O. lamifolium) plant. The I-optimal coordinate exchange randomized response surface methodology (RSM) was used to optimize the effect of the zinc acetate precursor, temperature, and time on ZnO NPs by designing nine runs. From ANOVA analysis, the significance and validity of the designed model showed that the optimal values of the zinc acetate precursor, temperature, and time during ZnO NPs synthesis were found to be ∼0.06 M, ∼30 °C, and ∼1.35 h, respectively. The obtained ZnO NPs under these optimized conditions were characterized and explored by UV-vis, TGA/DTA, FTIR, XRD, SEM-EDX, TEM, HRTEM, and SAED. Furthermore, the electrocatalytic performance of ZnO NPs was performed for sulfamethoxazole (SMZ) sensing activity with a 0.3528 μM (S/N = 3) limit of detection (LOD). In addition, an antibacterial study revealed that ZnO NPs confirmed an excellent zone of inhibition against E. coli, S. aureus, P. aeruginosa, and S. pyogen pathogenic drug resistance bacterial strains at concentrations of 50, 75, and 100 μg/mL. Thus, ZnO NPs synthesized using the O. lamifolium leaf have a potential electrocatalytic activity for diverse organic pollutant detection as well as a desirable material for such drug resistance antimicrobial strains.

Synthesis of zinc oxide nanoparticles using methanol propolis extract (Pro-ZnO NPs) as antidiabetic and antioxidant

In recent times, the overall health of individuals has been declining due to unhealthy lifestyles, leading to various diseases, including diabetes. To address this issue, antidiabetic and antioxidant agents are required to back-up human well-being. Zinc oxide (ZnO) is one such substance known for its antidiabetic and antioxidant effects. To enhance its capability and effectiveness, propolis was utilized to synthesize zinc oxide nanoparticles (Pro-ZnO NPs). The objective of this study was to synthesize Pro-ZnO NPs and assess their performance by conducting inhibition assays against α-amylase and α-glucosidase enzymes, as well as a 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. The results showed that Pro-ZnO NPs were formed in a hexagonal wurtzite structure, with particle sizes ranging from 30 to 50 nm and an absorption band observed at 341 nm. The stability, chemical properties, and crystallography of Pro-ZnO NPs were also thoroughly examined using appropriate methods. The Pro-ZnO NPs demonstrated significant inhibitory effects against α-amylase and α-glucosidase enzymes, with inhibition rates reaching 69.52% and 73.78%, respectively, whereas the antioxidant activity was as high as 70.76%. Consequently, with their high inhibition rates, the Pro-ZnO NPs demonstrate the potential to be employed as a natural agent for combating diabetes and promoting antioxidant effects.

Green nanocoating-based polysaccharides decorated with ZnONPs doped Egyptian kaolinite for antimicrobial coating paper

Paper coating plays an important role in the paper properties, printability and application. The nanocoating is a multifunction layer that provides the paper with unique features. In this work, nanocoating formulas were prepared using a green method and component. The nanocoating formulas were based on biopolymers nanostarch NSt and nanochitosan NCh (NCS) decorated with Egyptian kaolinite Ka doped with zinc nanoparticles NCS@xka/ZnONPs (x represents different ratios) support for multifunctional uses. The nanocoating formulas were characterized using a physiochemical analysis as well as a topographical study. FTIR, XRD, SEM and TEM techniques were used. Additionally, the antimicrobial activity of the tested samples was assessed against six microorganisms including Gram-negative and Gram-positive bacteria. The prepared nanocoating formulas affirmed excellent antimicrobial activity as a broad-spectrum antimicrobial active agent with excellent activity against all representative microbial communities. The nanocoating with the highest ratio of Ka/ZnONPs (NCS@40 ka/ZnONPs) showed excellent antimicrobial activity with an inhibition percentage of more than 70% versus all microorganisms presented. The paper was coated with the prepared suspensions and characterized concerning optical, mechanical and physical properties. When Ka/ZnONPs were loaded into NCS in a variety of ratios, the characteristics of coated paper were enhanced compared to blank paper. The sample NCS@40 ka/ZnONPs increased tensile strength by 11%, reduced light scattering by 12%, and improved brightness and whiteness by 1%. Paper coated with NCh suspension had 35.32% less roughness and 188.6% less porosity. When coated with the sample NCS@10 ka/ZnONPs, the coated paper's porosity was reduced by 94% and its roughness was reduced by 10.85%. The greatest reduction in water absorptivity was attained by coating with the same sample, with a reduction percentage of 132%.

An Insight into Citrus medica Linn.: A Systematic Review on Phytochemical Profile and Biological Activities

Plant species are a reservoir of natural compounds that can potentially be used to treat different diseases. Citrus medica Linn. belonging to the Rutaceae family, has been used for centuries in medicine for its antioxidant, anti-inflammatory, antimicrobial, antiviral, and antihyperglycemic properties. These activities are ascribable not only to the presence of health-promoting macronutrients and micronutrients, such as carbohydrates, minerals, amino acids, and vitamins, but also to specialized metabolites, such as flavonoids (apigenin, hesperetin, hesperidin, naringin, naringenin, rutin, quercetin, and diosmin), coumarins (citropten, scoparone, and bergapten), terpenes (limonene, γ-terpinene, limonin, and nomilin), and phenolic acids (p-coumaric acid, trans-ferulic acid, and chlorogenic acid). In recent years, particular attention has been focused on the antioxidant, anti-inflammatory, antimicrobial activity, antidiabetic, anticancer, and neuroprotective activity of C. medica. However, although many studies have reported this species' chemical and biological properties, the literature has never been analyzed via a systematic approach. For this reason, using PubMed and Scopus as databases, we performed a systematic review of C. medica's chemical composition and biological properties to inspire new research approaches and increase its curative application.

Fruit Peel Powder as Natural Antioxidant and Reinforcing Bio-Filler in Natural Rubber Latex Gloves: Cases of Mangosteen, Pomelo and Durian

As the world is facing rapid increases in agricultural wastes that greatly affect global health, the environment, and economies, this work aims to alleviate such issues by introducing simple uses of waste fruit peel powder (FPP) derived from mangosteen (MPP), pomelo (PPP), or durian (DPP), as dual natural antioxidants and reinforcing bio-fillers in natural rubber latex (NRL) gloves. A thorough investigation was undertaken of the relevant characteristics for both FPP (morphological, functional groups, particle sizes, and thermals stability) and NRL gloves (morphological, functional groups, density, color, thermal stability, and mechanical properties-both before and after thermal/25 kGy gamma aging). The results indicated that the initial addition (2-4 parts per hundred parts of rubber by weight; phr) of FPP to NRL composites generally enhanced the strength and elongation at the break of the specimens, with the levels of the improvement varying depending on the type and content of FPPs. In addition to the reinforcing effects, the FPP also offered natural antioxidant properties, evidenced by higher values of aging coefficients for all FPP/NRL gloves under either thermal or 25 kGy gamma aging than those of pristine NRL. Furthermore, by comparing the tensile strength and elongation at break of the developed FPP/NRL gloves with the requirements for medical examination latex gloves according to ASTM D3578-05, the recommended FPP contents for actual glove production were 2-4 phr for MPP, 4 phr for PPP, and 2 phr for DPP. Consequently, based on the overall outcomes, the FPPs of interest showed promising potential for utilization as simultaneous natural antioxidants and reinforcing bio-fillers in NRL gloves, which would not only enhance the strength and ability of the gloves to resist oxidative degradation from heat and gamma irradiation but also increase their economical value as well as reducing the amounts of the investigated wastes.

Cellulose-Based Metallogels-Part 1: Raw Materials and Preparation

Metallogels are a class of materials produced by the complexation of polymer gels with metal ions that can form coordination bonds with the functional groups of the gel. Hydrogels with metal phases attract special attention due to the numerous possibilities for functionalization. Cellulose is preferable for the production of hydrogels from economic, ecological, physical, chemical, and biological points of view since it is inexpensive, renewable, versatile, non-toxic, reveals high mechanical and thermal stability, has a porous structure, an imposing number of reactive OH groups, and good biocompatibility. Due to the poor solubility of natural cellulose, the hydrogels are commonly produced from cellulose derivatives that require multiple chemical manipulations. However, there is a number of techniques of hydrogel preparation via dissolution and regeneration of non-derivatized cellulose of various origins. Thus, hydrogels can be produced from plant-derived cellulose, lignocellulose and cellulose wastes, including agricultural, food and paper wastes. The advantages and limitations of using solvents are discussed in this review with regard to the possibility of industrial scaling up. Metallogels are often formed on the basis of ready-made hydrogels, which is why the choice of an adequate solvent is important for obtaining desirable results. The methods of the preparation of cellulose metallogels with d-transition metals in the present state of the art are reviewed.

Antibiofilm Efficacies of Flavonoid-Rich Sweet Orange Waste Extract against Dual-Species Biofilms

The current study evaluated the antibacterial properties of industrial sweet orange waste extracts (ISOWEs), which are a rich source of flavonoids. The ISOWEs exhibited antibacterial activity towards the dental cariogenic pathogens Streptococcus mutans and Lactobacillus casei with 13.0 ± 2.0 and 20.0 ± 2.0 mg/mL for MIC (minimum inhibitory concentration) and 37.7 ± 1.5 and 43.3 ± 2.1 mg/mL for MBC (minimum bactericidal concentration), respectively. When evaluated in a 7-day dual-species oral biofilm model, ISOWEs dose-dependently reduced the viable bacteria count, and demonstrated strong synergistic effects when combined with the anti-septic chlorhexidine (at 0.1 and 0.2%). Similarly, confocal microscopy confirmed the anti-cariogenic properties of ISOWEs, alone and in combination with chlorhexidine. The citrus flavonoids contributed differently to these effects, with the flavones (nobiletin, tangeretin and sinensetin) demonstrating significantly lower MICs and MBCs compared to the flavanones hesperidin and narirutin. In conclusion, our study demonstrated the potential of citrus waste as a currently underutilised source of flavonoids for antimicrobial applications, such as in dental health.

Biogenic fabrication and enhanced photocatalytic degradation of tetracycline by bio structured ZnO nanoparticles

ABSTRACTZinc oxide nanoparticles (ZnO NPs) were synthesized using Zinc Nitrate as precursor salt, and plant leaves extracts from Azadirachta indica (Common name: Neem), Cymbopogan citratus (Common name: Lemongrass), and Mangifera indica (Common name: Mango), as both chelating and reducing agents for the synthesis of ZnO NPs by a simple cost-effective and eco-friendly green method. The biosynthesized ZnO NPs were well characterized by various methods. XRD pattern revealed a hexagonal wurtzite phase of ZnO, with no other impurity peaks present revealing XRD crystalline sizes of 13.94-16.37 nm calculated using Scherrer equation. The XPS confirmed the presence of Zn, O, and C, and the carbon peaks are almost in agreement with peaks observed by FT-IR. TEM showed the different ZnO with spherical shapes and some aggregations. BET surface area gave 24.98, 21.62, and 22.72 m²/g, respectively for ZnO-AI, ZnO-Cyc, and ZnO-MI, while BJH pore volume and average pore diameter were estimated to be 0.217 cc/g, 0.209 cc/g, 0.211 cc/g, and 2.132 nm, 2.025 nm, and 2.100 nm respectively for ZnO-AI, ZnO-Cyc, and ZnO-MI.Furthermore, the bio-synthesized ZnO NPs were evaluated for their catalytic and photocatalytic performance in the degradation of aqueous tetracycline (TC). The biosynthesized ZnO NPs exhibit good photodegradation efficiency for TC in varying degrees with ZnO-AI > ZnO-MI > ZnO-Cyc. Optimum operational parameters for TC degradation using the ZnO-AI were established, and maximum degradation efficiency of 84.8% was obtained. In addition, the catalyst can also be regenerated and reused up to three cycles, with the third cycle still achieving greater than 80% TC degradation.