Plant-mediated Synthesis Research Articles

Plant-mediated synthesis, characterization, and evaluation of a copper oxide/silicon dioxide nanocomposite by an antimicrobial study

Abstract This study presents an innovative, environmentally friendly method for biosynthesizing copper oxide–silica (Cu2O/SiO2) nanocomposites (CSNCs) utilizing an aqueous leaf extract of Callistemon viminalis (C. viminalis). The goal of this work is to fabricate CSNCs using a less hazardous and sustainable synthesis approach. Copper acetate and sodium metasilicate were used as precursors, whereas the C. viminalis green leaf extract was used as the reducing and stabilizing agent. Analysis of the plant extract using Fourier transform infrared spectroscopy indicated the presence of polyphenolic compounds, primarily phenolic acids, which functioned as both reducing and stabilizing agents in the synthesis of CSNCs. A combination of energy dispersive X-ray spectroscopy and scanning electron microscopy was used to study the formation of spherical copper–silica hybrid nanostructures. Powder X-ray diffraction analysis revealed the successful integration of silica with copper(i) oxide (Cu2O) through the presence of distinct Cu2O peaks and a broad amorphous SiO2 peak at 2θ = 22.77°. The thermal stability of the nanocomposites (NCs) was assessed using thermogravimetric analysis and differential thermal analysis under a nitrogen atmosphere. The biogenic NCs also successfully inhibited pathogenic strains of Staphylococcus aureus (S. aureus) and Candida albicans (C. albicans); however, S. aureus was found to be more susceptible to the biocidal activity of the NCs than P. aeruginosa. These findings suggest that this simple, cost-effective, and eco-friendly method for producing biologically active hybrid nanomaterials holds significant promise for future applications in both biological and materials sciences.

Plant-mediated synthesis of biocompatible ZnO NPs: comprehensive characterisation and investigation of their catalytic, corrosion inhibition, antibacterial, scavenging and anti-oncogenic activities

ABSTRACT In this study, we present a novel method for synthesising zinc oxide nanoparticles (ZnO NPs) from the dried Caesalpinia sappan seeds powder. Comprehensive characterisation using XRD, FTIR, SEM, and EDX techniques was employed to elucidate the surface and morphological properties of these ZnO NPs. We showcase the versatile application of ZnO NPs as heterogeneous catalyst in the synthesis of 5-arylmethylidene-pyrimidin-2,4,6-triones. Notably, this eco-friendly approach eliminates the need for organic solvents, offering a sustainable route to producing 5-arylmethylidene-pyrimidin-2,4,6-triones in high yields. Furthermore, we investigate the corrosion inhibition properties of ZnO NPs on mild steel in 5% sodium chloride solution. Our findings reveal the ZnO NPs’ significant inhibition efficiency against corrosion, promising potential for practical applications. In addition to their chemical applications, we delve into the biological activities of ZnO NPs, including their antibacterial effects against both Gram-positive and Gram-negative bacteria, anti-oncogenic activity against DU-145 cells, and scavenging activities against oxidative stress.

Comparative study of photo catalytic activity of Tinospora Cordifolia derived nanoparticles for degradation of indigo carmine

Plant-mediated synthesis of nanoparticles has emerged as an important field in synthesis of nanoparticles (NPs) as fewer chemicals are being used, method is cost-effective and also fulfils principles of green chemistry. Due to the rapid growth of industries in recent times, there has been an increase in concentration of dyes in water, which causes problems and affects human and animal’s health. Moreover, nanoparticles has emerged as an effective solution for dye degradation due to their effective catalytic activity. In the current work, we carried out a comparative study on Tinospora Cordifolia, derived oxide nanoparticles for degrading Indigo Carmine. The characterization of formed particles have been done by techniques like XRD, SEM, FTIR and EDX. The effectiveness of the synthesized nanoparticles as photo catalyst in removing indigo carmine was assessed by emphasizing on important aspects such as amount of catalyst, concentration of dye, and the pH. The results showed SnO2 nanoparticles exhibited superior degrading activity compared to CuO. The optimal dose for SnO2 NPs was 0.25 g/L, while for CuO, it was 0.50 g/L. When pH was altered, it was observed that acidic environment exhibited superior breakdown ability. The optimal degradation capability was observed at dye concentration of 40 parts per million (ppm).

Carya Illinoinensis-mediated Green Synthesis and Antimicrobial Screening of Zirconium Oxide Nanoparticles: The Promising Antimicrobial Agent

Background: The synthesis of metal-based nanoparticles through conventional methods involves harsh conditions, high costs, and severe environmental threats. To overcome these issues, researchers are nowadays focusing on eco-friendly and low-cost methods for the synthesis of nanoparticles. Finally, several plant-mediated synthesis techniques have been developed, which have various advantages, such as low-cost, environmentally friendly, and easy application. The plant extract not only serves as a reducing agent but also plays a role as a stabilizing agent. The plantmediated synthesis provides new opportunities for cost-effective, environmentally-friendly nanoparticle synthesis with high dispersity and stability. Besides, bio-generated nanoparticles derived from plant extract have promising pharmacological applications, making them potential candidates for future medicines. Aims and Objectives: The current study aimed to synthesize zirconium oxide nanoparticles using Carya illinoinensis extract and examine their physicochemical properties. Additionally, the antimicrobial efficacy of these nanoparticles was evaluated against various pathogens, exploring their potential as potent antimicrobial agents. Method: The synthesized nanoparticles were analyzed and characterized by various techniques like UV-Vis spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Energy Dispersive X-ray spectroscopy (EDX). The UV-visible peak at 216 nm confirmed the formation of ZrO2 nanoparticles. The SEM images clearly showed that nanoparticles were spherical and relatively dispersed, with few agglomerations. The EDX spectra confirmed the existence of zirconium and oxygen as the basic constituents of the sample. TEM images demonstrated nanoparticles as spherical and uniformly dispersed but agglomerated with increasing precursor concentrations and decreasing nanoparticle dispersion. Fluconazole and gentamicin were used as standards in determining the antibacterial and antifungal activities of nanoparticles. Results: Considering the antifungal activity, a maximum zone of inhibition of 16 μg/ml was demonstrated in the case of 2 mM as compared to 4 mM and 6 mM concentrations. The Carya illinoinensismediated ZrO2 nanoparticles were screened against Gram-positive (S. aureus and P. aeruginosa) and Gram-negative (S. typhi and E. coli) bacterial strains. The fabricated nanoparticles exhibited promising action against all microorganisms. Conclusion: In the current study, zirconium oxide nanoparticles were synthesized by using Carya illinoinensis leaves extract as a reducing agent. The antifungal and antibacterial potential of the synthesized nanoparticles were evaluated. The green synthesis method used in this study is preferable to the others as it is more affordable, environmentally benign, and widely accessible.

Green synthesis of silver nanoparticles from Brassaiopsis hainla extract for the evaluation of antibacterial and anticorrosion properties

Plant-mediated synthesis of silver nanoparticles (AgNPs) is an eco-friendly and convenient alternative to conventional methods. Brassaiopsis hainla (B. hainla) leaf extract (BHE) was used in this study to reduce metal salts and cap and stabilize nanoparticles (NPs), which were characterized and tested for antibacterial and anti-corrosion properties. Stirring the B. hainla extract with AgNO3 led to a color change, indicating nanoparticle formation. The absorption peak at 428 nm in the UV–visible spectrum further validated its formation. The AgNPs were characterized using various techniques such as FTIR, UV–visible, PXRD, HRTEM, SEM, and EDX. Powder X-ray diffraction analysis confirmed its nanocrystalline nature, with an average crystallite size of 17.92 nm. The FTIR spectrum showed hydroxyl, amine, amide, and carbonyl groups as capping and reducing agents for the AgNPs. SEM analysis revealed poly-dispersed NPs of various sizes, while EDX showed an intense peak for Ag, and TEM images revealed mostly hexagonal and triangular NPs. Antibacterial activity was tested against three human pathogens: Staphylococcus aureus (S. aureus), Pseudomonas, and Klebsiella oxytoca (K. oxytoca). Significant antibacterial activity was observed specifically against K. oxytoca, with an 11 mm inhibition zone. Both plant extracts and AgNPs inhibited acid-induced corrosion, with the highest inhibition efficiencies of 81.69 % and 69.54 % at 1000 ppm, respectively. With rising concerns over bacterial resistance and metal corrosion, this study addresses global challenges related to new antimicrobial agents, which are crucial for combating antibiotic resistance and protecting metals in various industries.

Green Synthesis of Phyllanthus Niruri Nanoparticles for the Treatment of Sickle Cell Anemia

Nanotechnology is currently the most active research area in modern materials science. While numerous chemical and physical methods exist for the synthesis of nanomaterials, the green synthesis approach is increasingly prominent. Plant-mediated synthesis of nanoparticles is a green chemical technique that integrates nanotechnology with botany. This novel method of synthesis ideally occurs at ambient temperatures, neutral pH, and is cost-effective and environmentally friendly. Given this goal, various routes have been explored for synthesizing nanomaterials. The present study aims to formulate and evaluate herbal nanoparticles derived from Phyllanthus niruri for the natural treatment of sickle cell anemia. Sickle cell anemia is characterized by the presence of sickle-shaped erythrocytes caused by abnormal hemoglobin production. This condition leads to clogging of capillaries and obstructs blood flow in the vessels, resulting in severe complications such as ischemia, hypoxia, and organ failure. While some drugs, such as hydroxyurea, are available for treating sickle cell anemia, they are often associated with severe adverse effects, limiting their frequent use. Therefore, this study focuses on designing herbal nanoparticles as an alternative treatment for sickle cell anemia. The plant material for this study was sourced from an authorized market, dried, and powdered for further processing.

Plant-Mediated Synthesis of Yttrium Oxide Nanoparticles vs. Traditional Methods: Current Trends and Potential Applications

Plant-Mediated Synthesis of Yttrium Oxide Nanoparticles vs. Traditional Methods: Current Trends and Potential Applications

Biosurfactant assisted synthesis and characterization of silver nanoparticles: In vitro investigation of their anti-oxidant, anti-inflammatory, anti-infective and wound healing potential

Silver nanoparticles (AgNPs) hadshowen immense potential for managing inflammatory responses, oxidative stress, and severe microbial infections leading to chronic wounds by reducing environmental impact and resistance. Plant-mediated synthesis offers eco-friendly solutions, especially in degrading harmful textile dyes, benefiting ecosystems. Still, frequent aggregation and destabilization are the major limitations of metallic nanoparticles. Mannosylerythritol (MST), a lipid derived from microorganisms stabilises metallic nanoparticles. AgNPs were prepared by a chemical reduction method, characterized for optical, surface properties, and elemental analysis, and evaluated for ionic silver release, antioxidant effect, inhibition of ROS generation and NF-kB upregulation, anti-infective and wound closure potentials. The AgNPs comprised of 0.04% w/v AgNO3, 0.3% w/v sodium borohydride and 0.5% w/v MST exhibited nanosized (50–80 nm) orbicular particles with high purity and stability. EDX analysis portrayed the presence of 92.82% Ag by weight. Unlike acidified AgNPs, plane AgNPS showed consistent Ag+ release for 24 h, owing to which this group showed tremendous utility in scavenging DPPH-induced free radicals (20-fold lesser IC50 value) with a slight decrease in RAW 264.7 cell viability when tested by MTT assay. The MIC of AgNPs against C. albicans, S. aureus and P. aeruginosa was 10, 10 and 5 ppm, respectively. The microbial GI of AgNPs was found to be 62.44 ppm against C. albicans, 110.69 against S. aureus and 91.58 against P. aeruginosa. Flowcytometry showed a reduction in ROS generation, and NF-κβ upregulation justifies the safer use of AgNPs against oxidative stress and inflammatory conditions. The in vitro scratch test in RAW 264.7 cells justifies the rapid wound closure claim. Controlling a wide range of pathogens while mitigating oxidative stress and inflammation is the optimal strategy for expediting wound healing. Consequently, these AgNPs hold significant promise as innovative wound dressing materials for the future.

Zero-valent Iron Nanoparticles: Biogenic Synthesis and their Medical Applications; Existing Challenges and Future Prospects.

In the last decade, nanobiotechnology is emerging as a keen prudence area owing to its widespread applications in the medical field. In this context, zero-valent iron nanoparticles (nZVI) have garnered tremendous attention attributed to their cheap, non-toxic, excellent paramagnetic nature, extremely reactive surface, and dual oxidation state that makes them excellent antioxidants and free-radical scavengers. Facile biogenic synthesis, in which a biological source is used as a template for the synthesis of NPs, is presumably dominant among other physical and chemical synthetic procedures. The purpose of this review is to elucidate plant-mediated synthesis of nZVI, although they have been successfully fabricated by microbes and other biological entities (such as starch, chitosan, alginate, cashew nut shell, etc.) as well. The methodology of the study involved keyword searches of electronic databases, including ScienceDirect, NCBI, and Google Scholar (2008-2023). Search terms of the review included 'biogenic synthesis of nZVI', 'plant-mediated synthesis of nZVI', 'medical applications of nZVI', and 'Recent advancements and future prospects of nZVI'. Various articles were identified and reviewed for biogenic fabrication of stable nZVI with the vast majority of studies reporting positive findings. The resultant nanomaterial found great interest for biomedical purposes such as their use as biocompatible anticancer, antimicrobial, antioxidant, and albumin binding agents that have not been adequately accessed in previous studies. This review shows that there are potential cost savings applications to be made when using biogenic nZVI for medical purposes. However, the encountering challenges concluded later, along with the prospects for sustainable future development.

Facile green fabrication of magnetite nanoparticles using an aqueous flower extract of Murraya paniculata (L) Jack for an efficient removal of organic dye pollutant, antibacterial activities

This article reports, the plant-mediated synthesis of Magnetite nanoparticles achieved by utilising an aqueous flower extract of Murraya paniculata (L) Jack (FMPM NPs). The active compounds are phenols, alkaloids, flavones and terpenoids in the aqueous flower extract of Murraya paniculata act as ligating agents to synthesize novel green superparamagnetic magnetite nanoparticles by the coprecipitation method. As prepared FMPM NPs have been characterized by a range of spectroscopic and microscopic techniques. All spectroscopic and microscopic results confirmed the occurrence of pure FMPM NPs. Fourier transform-infrared spectroscopy (FTIR) shows the presence of a Fe-O bond and the band gap was found to be 2.57 eV for FMPM NPs. The surface area of the synthesized nanoparticles was 70.31 m2/g evaluated by BET analysis. The elemental analysis has been performed by the XPS technique. The XRD pattern revealed the crystal size of 14.12 nm of FMPM NPs. TEM images show the spherical shaped FMPM NPs with an average particle size of 11.58 nm. SEM results clearly show spherically shaped FMPM NPs. The superparamagnetic character of FMPM NPs is revealed by the VSM curve and saturation magnetization (Ms) value of 58 emu/g. FMPM NPs used for photocatalytic activity, tested against gram positive, gram negative and antifungal bacteria. As prepared FMPM NPs. showed 93 % removal efficiency of Fast sulphon black-F dye pollutant. Moreover, FMPM NPs efficiently inhibit the growth of Enterococcus faecalis and Penicillium chrysogenum. The current research is for the fabrication of magnetite nanoparticles utilising novel green source and examining their applications.

Plant-mediated synthesis of silver nanoparticles: unlocking their pharmacological potential-a comprehensive review.

In recent times, nanoparticles have experienced a significant upsurge in popularity, primarily owing to their minute size and their remarkable ability to modify physical, chemical, and biological properties. This burgeoning interest can be attributed to the expanding array of biomedical applications where nanoparticles find utility. These nanoparticles, typically ranging in size from 10 to 100nm, exhibit diverse shapes, such as spherical, discoidal, and cylindrical configurations. These variations are not solely influenced by the manufacturing processes but are also intricately linked to interactions with surrounding stabilizing agents and initiators. Nanoparticles can be synthesized through physical or chemical methods, yet the biological approach emerges as the most sustainable and eco-friendly alternative among the three. Among the various nanoparticle types, silver nanoparticles have emerged as the most encountered and widely utilized due to their exceptional properties. What makes the synthesis of silver nanoparticles even more appealing is the application of plant-derived sources as reducing agents. This approach not only proves to be cost-effective but also significantly reduces the synthesis time. Notably, silver nanoparticles produced through plant-mediated processes have garnered considerable attention in recent years due to their notable medicinal capabilities. This comprehensive review primarily delves into the diverse medicinal attributes of silver nanoparticles synthesized using plant-mediated techniques. Encompassing antimicrobial properties, cytotoxicity, wound healing, larvicidal effects, anti-angiogenesis activity, antioxidant potential, and antiplasmodial activity, the paper extensively covers these multifaceted roles. Additionally, an endeavor is made to provide an elucidated summary of the operational mechanisms underlying the pharmacological actions of silver nanoparticles.

Exploration of Ascochyta rabiei diversity through various molecular tools and control of its pathogenic strain via green synthesized zinc oxide nanoparticles

Fungus is the most important disease-causing biotic factor on earth. The study of their genetic diversity is very important for their management and control. For studying Ascochyta rabiei on chickpea blight chickpea samples caused by Ascochyta rabiei were collected and disease-causing organisms were isolated from infected plant parts and their ITS region was sequenced. BLAST analysis revealed that A. rabiei is the causal pathogen of this blight disease. Phylogenetic analysis suggested great diversity among these isolates of A. rabiei. The results confirm that A. rabiei strains collected from Bannu and Lakki Marwat have genetic similarities but are different from other isolated strains of the same species. Similarly, studied strains from Kamber, Shadat Kot, and Larkana. Khairpur and Bhakkar were also similar. However, strains from Khushab and Mianwali showed genetic differences from each other. The current research also reports the plant-mediated synthesis of ZnO NPs via the plant extract of Thevetia peruviana. The ZnO NPs were characterized through UV, XRD, FTIR, FE-SEM, EDX, and the size of the nanoparticle of 28 nm was calculated. The prepared nanoparticle was used for the antifungal activity against the most severe strain of A. rabiei. The Biosynthesis of ZnO NPs by plant assets is an eco-friendly, consistent process and appropriate for extensive production.

A Review on the Green Synthesis of ZnO Nanoparticles Using the Aqueous Extract of Origanum Majorana for Antimicrobial Applications

Zinc oxide nanoparticles (ZnO-NPs) have been extensively researched for their potential applications in various fields such as pharmaceuticals, cosmetics, biotechnology, sensing, photocatalysis, and photovoltaics due to their unique nanoscale properties. However, the conventional methods for producing ZnO NPs require the use of hazardous chemicals and high energy consumption, which imposes certain limitations. In contrast, the green synthesis of ZnO-NPs using plant extracts, especially Origanum majorana, has gained much attention as a promising alternative approach. Plant extracts contain phytochemicals that are biologically safe and non-toxic, making them a preferred choice. In addition, the ZnO-NPs synthesized with O. majorana extracts exhibit higher stability and can be customized in terms of shape and size, unlike the ZnO-NPs obtained by bacterial or fungal methods. The aqueous leaf extract of O. majorana contains flavonoids, tannins, and phenolic derivatives, which serve as reducing and capping agents for the biosynthesis of ZnO-NPs. These extracts also contain functional groups such as -OH and -C=O, which further enhance the physicochemical properties of the resulting ZnO-NPs and influence their ability to target specific molecules. The plant-mediated synthesis of ZnO-NPs using O. majorana leaf extract is not only fast and straightforward but also offers a wide range of functionalized nanoparticles with specific morphologies and sizes. These ZnO-NPs prepared with O. majorana have been shown to have potential applications in various fields, including antimicrobial, antioxidant, and anticancer activities. This review focuses specifically on the antimicrobial applications of ZnO-NPs synthesized using O. majorana leaf extract.

Bio-fabrication, characterization and biological properties of zinc oxide nanoparticles (ZnO-NPs) from scarlet morning glory- Ipomoea hederifolia

Zinc oxide nanoparticles (ZnO-NPs) are a topic of substantial interest for their unique catalytic, magnetic, electrical, optical, and biological properties. It has been noted that plant-mediated synthesis of these nanoparticles has gained attention due to limitations in the chemically synthesized particles, which are also found hazardous to the environment. In the study, the leaf extract of Ipomoea hederifolia L. was utilized to bio-fabricate ZnO-NPs (Ih-ZnO-NPs) and is the earliest to describe the bio-fabrication of ZnO-NPs using the plant and its biological properties. UV–Vis Spectroscopy, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and Fourier transform infrared spectroscopy (FT-IR) were used to elucidate the structural characters of bio-fabricated Ih-ZnO-NPs. The structural characterization studies revealed that Ih-ZnO-NPs are of hexagonal shape, ∼20 nm size and high purity. Aggregation of Ih-ZnO-NPs was noticed under the SEM with a purity of 98 % when analyzed through EDS. The Ih-ZnO-NPs offered significant antibacterial properties with an MIC of 0.312 mg mL−1 for S. aureus and B. subtilis followed by 0.625 mL−1 and 1.25 mg mL−1 for E. coli and S. typhi, respectively. In addition, the antioxidant and antimitotic investigation found that the particles had a dose-dependent activity with an IC50 of 0.94 mg mL−1 and 1.59 mg mL−1, respectively. The results demonstrate that these bio-fabricated ZnO-NPs can be utilized as an alternative to current chemical components after further validation.

Plant-mediated synthesis of thermally stable metal-polystyrene nanocomposites for antioxidant and antibacterial food packaging

Annually, millions of individuals are hospitalized worldwide because of illnesses attributed to foodborne pathogens. With the surge in foodborne diseases, the importance of reliable and optimized food packaging has become more crucial than ever. Okra (Abelmoschus esculentus) seed extract was utilized as a mediator for synthesizing thermally stable nanoparticles (NPs) of Fe0, Zn0, Ag0, Fe2O3, ZnO, and Ag2O. These NPs were subsequently incorporated into polystyrene (PS) sheets to fabricate NPs-PS composites. Nanoparticle synthesis with a uniform morphology and size range of 20–60 nm was confirmed through various characterization techniques, including surface plasmon resonance, Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray (EDX) techniques. The antioxidant potential, as determined by the 2,2-diphenylpicrylhydrazyl (DPPH) free radical scavenging and Phosphomolybdenum assay, followed the order of Silver > Iron > Zinc. Conversely, the antimicrobial potential, evaluated through the agar well diffusion method, was in the order of Silver ≈ Zinc > Iron. Zero-valent metal NPs and NPs-PS Composites exhibited superior results compared to metal oxide NPs and NPs-PS Composites. Lemon and Apple slices wrapped in NPs-PS composite sheets exhibited significantly improved shelf life compared to pure PS, demonstrating the high effectiveness of metal NPs modified composites for food packaging by protecting it from oxidative decay and microorganisms.

Synthesis of Zinc Oxide Nanoparticles and Their Applications in Enhancing Plant Stress Resistance: A Review

Biotic and abiotic stress factors are pivotal considerations in agriculture due to their potential to cause crop losses, food insecurity, and economic repercussions. Zinc oxide nanoparticles (ZnO nanoparticles) have gained substantial attention from researchers worldwide for their capacity to alleviate the detrimental impacts of both biotic and abiotic stress on plants, concurrently reducing dependence on environmentally harmful chemicals. This article provides an overview of methods for synthesizing ZnO nanoparticles, encompassing physical vapor deposition, ball milling, hydrothermal methods, solvothermal methods, precipitation methods, microwave methods, microbial synthesis, and plant-mediated synthesis. Additionally, it delves into the absorption, translocation, and biotransformation pathways of ZnO nanoparticles within plants. The emphasis lies in elucidating the potential of ZnO nanoparticles to safeguard plants against biotic and abiotic stress, enhance plant performance, and modulate various plant processes. The article also offers a preliminary exploration of the mechanisms underlying plant stress tolerance mediated by ZnO nanoparticles. In conclusion, ZnO nanoparticles present an environmentally friendly and cost-effective strategy for plant stress management, paving the way for the integration of nanotechnology in sustainable agriculture. This opens new possibilities for leveraging nanotechnology to bolster plant resilience against stress in the ever-changing climate conditions, ensuring global food security.

Metal Oxide Nanoparticles’ Green Synthesis by Plants: Prospects in Phyto- and Bioremediation and Photocatalytic Degradation of Organic Pollutants

Over the past few decades, the production of metal oxide nanoparticles (MONPs) has developed into an exciting and sophisticated research area. Green metal oxide nanoparticles have played an extremely imperative role in various fields, including biomedical, environmental, energy, agricultural applications, catalytic, bioactive, antibacterial, poisonous, and biocompatible. To achieve sustainability and adopt environmentally friendly practices, the production of MONPs is now increasingly focused on exploring green chemistry and alternative pathways. When made using green synthesis techniques, the metal oxide nanoparticles are especially important because they do not require external stabilizers, capping agents, dangerous chemicals, or harsh operating conditions (high pressure and temperature). Plant-mediated synthesis of different MONPs using either whole cells or extracts has several advantages, including rapid synthesis (compared with other biogenic processes (using fungi and bacteria)), being more stable than other types, being available in nature, and being non-toxic. This review provides a comprehensive overview of the green synthesis of MONPs using plant parts, factors affecting the synthesis, and the characterization of synthesized NPs. Additionally, it highlights the potential of these environmentally friendly nanoparticles that are widely used to treat environmental pollutants, including the removal of heavy metals, antibacterials, and the degradation of organic pollutants.

Biogenesis and Green Synthesis of Metal Nanoparticles and Their Pharmacological Applications

Nanomaterial innovation is the primary catalyst of advancement in nanotechnology. Although there are many known chemical processes for creating nanoparticles that use harmful substances, it is now more important than ever to use processes that are safer, greener, and more environmentally friendly. The goal of research in this field is to use diverse life forms as "nanoparticle factories." Phytochemicals can convert salt into the appropriate nanoparticles thanks to their regular biosynthetic routes. In recent years, green chemistry methods for the synthesis of metallic nanoparticles have emerged as a fresh and exciting area of study. Metal nanoparticles, including gold (Au), silver (Ag), iron (Fe), and cadmium (Cd) along with certain oxides, can be synthesized using a variety of chemical and physical techniques as well as biological techniques carried out using plants. It has been discovered that methods involving plant-mediated synthesis are a more efficient and cost-effective way to create these metal nanoparticles. The plant-mediated nanoparticles are used as potential pharmaceutical agents for many diseases, including hepatitis, cancer, malaria, and HIV. Due to the higher efficacy and fewer side effects of nanodrugs compared to other commercial cancer drugs, the synthesis of nanoparticles targeting biological pathways has gained tremendous popularity. This review paper aims to cover the different green methods for the biogenesis of these nanoparticles, the different compounds and salts used, and the metals obtained. Ultimately, the significance and prospects of these metal nanoparticles especially in the fields of medicine, pharmacology, drug designing, and drug delivery engineering will also be commented on.

BIOGENIC SYNTHESIS AND ANTIBACTERIAL ACTIVITIES OF CERIUM OXIDE AND ZINC OXIDE NANOPARTICLES ON FISH PATHOGENS

Plant-mediated synthesis of nanoparticles has gained much attentions due to its eco-friendliness, non-toxic, ease of preparation and biocompatibility. Phytochemicals has been adjudged to be useful as bio-reductants, stabilizers, and capping agents in the formation of nanoparticles. The aim of this study is to compare the antibacterial activities of biosynthesized Cerium oxide (CeO2NPs) and Zinc oxide nanoparticles (ZnONPs) against fish pathogens (Vibrio cholera strain RC3 and Escherichia coli strain C214). Qualitative analysis of Carica papaya leaf extract was performed to examine the biomolecules present, then biosynthesis was carried out. CeO2NP and ZnONP formed were characterized through UV-visible spectrophotometry, scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction analysis, and Fourier transformed infrared spectroscopy to confirm the formation of the nanoparticles. The result revealed monodispersed, spherical shaped CeO2NPs with average size of 46.34nm, while ZnONP revealed cylindrical shaped nanoparticles with average size of 43.77nm. Antibacterial sensitivity test showed that CeO2NP has a higher antibacterial potential than ZnONPs on Vibrio cholera (13.00±1.41b and 10.00±1.41c) and E. coli (8.00±1.41b and 0.00±0.00a). In view of this outcome, it is therefore suggested that CeO2NP could be used effectively against Vibrio cholera strain RC3 and E. coli strain C214 than ZnONP with highly significant impact.

Microwave-assisted phytogenic Ag/Ag2O/ZnO nanocomposite as a replacement of Ag/Ag2O and ZnO nanoparticles: A comparative antioxidant study

A biogenic approach, particularly plant-mediated synthesis, is currently regarded as the sustainable approach for synthesizing nanomaterials (NMs). The present investigation concentrates on the green fabrication of Ag/Ag2O nanoparticles (NPs), ZnO NPs, and Ag/Ag2O/ZnO nanocomposites (NCs) via microwave irradiation using Murusi peel (MP) and Kew peel (KP) aqueous extracts and comparatively determine their antioxidant potentials. The synthesis parameters of Ag/Ag2O NPs, ZnO NPs, and Ag/Ag2O/ZnO NCs were optimized and characterized using different analytical techniques. Surface plasmon resonance peaks appeared at 448–450 nm, 350–370 nm, and 400–500 nm for Ag/Ag2O NPs, ZnO NPs, and Ag/Ag2O/ZnO NCs, respectively. The scanning electron microscopic images of both peel-mediated Ag/Ag2O NPs depicted quasi-spherical shapes aggregating on the flake-shaped ZnO surface, leading to the Ag/Ag2O/ZnO NCs formation. Transition electron microscopic analysis revealed the average particle sizes of MP and KP-mediated Ag/Ag2O NPs, ZnO NPs, and Ag/Ag2O/ZnO NCs as 13.58±1.32 nm, and 36.79±1.24 nm, 13.00±1.26 nm, and 10.28±1.25 nm, 28.37±1.39 nm, and 11.21±1.06 nm, respectively. X-ray diffraction analysis confirmed the synthesis of pure crystalline structures with a hexagonal wurtzite structure for ZnO and a face-centered structure for Ag and Ag2O during the formation of Ag/Ag2O/ZnO NCs. According to the research findings, MP and KP-mediated Ag/Ag2O/ZnO NCs displayed an enhanced free radical scavenging effect for DPPH (2,2-diphenyl-1-picrylhydrazyl) assay with IC50 values of 54.13±0.53 ppm and 51.41±1.27 ppm, respectively. At higher concentrations, the NCs exhibited a greater radical scavenging potential for ABTS (2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) assay, with the IC50 values for MP and KP-mediated as 72.28±0.83 ppm and 65.78±1.29 ppm, respectively. Similarly, for the FRAP (Ferric reducing antioxidant power) assay, MP and KP-mediated Ag/Ag2O/ZnO NCs demonstrated a higher antioxidant potential, expressed in terms of ascorbic acid equivalents (AE), which were 46±0.7 (AE) mg/1 g and 50±1.1 (AE) mg/1 g, respectively. To the best of our knowledge, this study remains the first comparative analysis of synergistically enhanced antioxidant potential of the agro-waste mediated Ag/Ag2O/ZnO NCs with their respective NPs counterparts, Ag/Ag2O NPs and ZnO NPs. These research findings pave the path for sustainably utilizing these NMs in biomedical applications.