Eco-friendly Green Synthesis Research Articles

Eco-Friendly Green Synthesis of Chromium Oxide Nanoparticles and Their Characterization and Application

In recent years the nanoparticle design synthesis methods conducted by plants replaced the traditional chemical procedures of nanoparticles preparations. This study demonstrates the environmental kindly preparations of chromium oxide nano particles (Cr2O3-NPs) using leaf extract of Mentha pulegium plant. The obtained Cr2O3-NPs was characterized by Ultra Violet /Visible spectroscopy, Fourier Transform Infra-Red (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectrophotometer (EDX) and X-ray diffraction studying. The presence of the Sharp peak at 462 nm in the Ultraviolet/Visible spectrum and the color changed by surface plasma resonance explains that Cr2O3-NPs is formed. The presence of oxygen and chromium in Cr2O3-nanoparticles is reported by EDX spectrum, which was found to consist of 32.57% Cr and 44.41% O, confirming the high purity of the Cr2O3-NPs powder. Since Scan Electron Microscope studying reported an irregular round morphology shape. In addition, X-ray diffraction studying suggested their crystalline feature by the characteristic peaks at 2θ= 24.3°, 33.5°, 36.2°, 41.5°, 50.3°, 54.8°, 63.4°, and 65.2°, respectively. The average crystallite size for Cr2O3-NPs was found to be 58 nm. The photo catalytic activity of green synthesized chromium oxide-NPs was also analyzed.

Biogenic synthesis of MgO nanoparticles using Arbutus Unedo leaf extract for removal of Bemacid Red from wastewater: Optimizing using BBD-RSM and ANN approach

Magnesium oxide nanoparticles were synthesized using leaf extracts from the Arbutus unedo plant through a sustainable and eco-friendly green synthesis approach. The efficacy of magnesium oxide nanoparticles in removing Bemacid Red dye was assessed by optimizing the removal process using a synergistic approach of artificial neural network and response surface methodology. Magnesium oxide nanoparticles were characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, thermogravimetric analysis, and X-ray fluorescence, confirming their well-defined crystalline structure, successful synthesis of pure MgO with an average particle size of 12.22 nm, and excellent thermal stability. Removal efficiency of 98.34 % was achieved at an adsorbent mass of 0.5 g. L−1, a temperature of 25 °C, an initial dye concentration of 80 mg. L−1, and a contact time of 20 min. The Langmuir adsorption model was selected to describe the adsorption of Bemacid Red onto the surface of magnesium oxide nanoparticles with an R2 value of 0.98, showing a maximum adsorption capacity of 632.91 mg. g−1. These findings underline the potential of magnesium oxide nanoparticles for sustainable wastewater treatment applications in various industrial sectors.

From agro-food waste to nanoparticles: green synthesis of copper nanoparticles with lignin peroxidase enzyme produced by Anoxybacillus rupiensis using peanut shells.

This study presents a novel approach for the eco-friendly green synthesis of copper nanoparticles (Cu NPs) using enzymatic mediation which is an environmentally benign alternative to conventional methods, offering control over particle size and shape. Anoxybacillus rupiensis BS1 thermophilic bacterium was isolated from Erzurum's Pasinler hot spring and lignin peroxidase enzyme production conditions (incubation time 96h, 40g/L shell amount, pH 8.5, 150rpm, and 60°C temperature) were used in the production of peroxidase enzyme using peanut waste which has been optimized. The characterization of the synthesized Cu NPs was performed using various analytical techniques, including UV-vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM), confirming the successful production of stable and well-defined nanoparticles. Furthermore, the biological activities of the synthesized Cu NPs were explored, revealing their potential for antimicrobial applications. The antibacterial efficacy of the Cu NPs against some pathogens such as Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Streptococcus pyogenes, and Bacillus cereus was examined. It was determined that Cu NPs were effective on all pathogens and had the highest effectiveness against the S. pyogenes pathogen (19.0mm). This study not only presents an innovative and sustainable approach for the synthesis of Cu NPs but also highlights the multifaceted biological activities of these nanoparticles, opening avenues for diverse applications in the fields of medicine, agriculture, and environmental remediation. The utilization of peanut shell wastes as a substrate for enzyme production adds value to agricultural by-products, contributing to the development of a circular and sustainable economy.

Synthesis of ZnO nanoparticles from the medicinal plant Salvia fruticosa Mill.: Green approach for potential biomedical application against Zn deficiency in humans

We hypothesized that we could prepare ZnO nanoparticles (ZnO NPs) as a biomedical application treatment of zinc deficiency in human populations. In this study, we report a formulation prepared using a low-cost method for the green synthesis of ZnO NPs by utilizing the medicinal species Salvia fruticosa as natural raw material and Zn(NO3)2∙6H2O as a Zn source. The final product was identified and characterized by elemental analysis using X-ray energy-scattering spectroscopy (EDS), ultraviolet–visible spectroscopy (UV-VIS Spectroscopy), X-ray powder diffraction (XRD), and morphometric analysis using scanning electron microscopy (SEM). Finally, crystallization was studied using transmission electron microscopy (TEM). Afterward, ZnO NPs thus produced were utilized for foliar spraying on S. fruticosa open cultures, and Zn fortification in the foliage. Then, their effects on the biosynthesis of essential oils, and Zn bioavailability to humans were studied through different modes of consumption.ZnO NPs produced using our method were spherical while some were hexagonal, with an average size of approximately 22 nm, based on XRD results. The green synthesis method devised in this study afforded ZnO NPs from Zn(NO3)2∙6H2O with a 95 % yield, and consequently yielded economic benefits with respect to the current market prices. Foliage Zn fortification and the desired features were successfully achieved using ZnO NPs, and the proper mode of consumption of this medicinal plant has been recommended in this study.In conclusion, the methodology described in this study enables eco-friendly green synthesis of ZnO NPs at a low cost using S. fruticosa and puts forward a contemporary and integrated biomedical use of ZnO NPs to treat disorders resulting from or related to Zn deficiency.

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

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

Terbium (III) and salicylamide doped nickel ferrite (NiFe2O4) nanoparticles synthesized from Olea europaea L. plant extracts via eco-friendly green synthesis approach and co-precipitation method

An eco-friendly and cost-effective NiFe2O4 nanoparticles and its derivatives NiFe2O4:salicylamide, NiFe2O4:salicylamide:Tb3+ and NiFe2O4:salicylamide:Tb3+:Olea europaea L. extracts have been successfully synthesized using a simple and refluxed-assisted chemical co-precipitation method and green route approach followed by thermal treatment steps. In this report, the structural, morphological, optical characteristics and biological activities of the nanoparticles were characterized by using XRD, SEM, FTIR, UV-Vis, PL, BET analysis, antibacterial assays and antioxidant activities. The results from XRD revealed that NiFe2O4 has a crystalline structure and EDX elemental mapping confirmed the uniform distributed of all the elements in the matrix. The incorporation of salicylamide, Tb3+ and Olea europaea L. extracts into NiFe2O significantly enriched the luminescence intensities and changed the emission colour coordinates. Colour tunability was achieved with luminescence ranging from bright blue emission to reddish orange light, which makes nanoparticles important candidates for solid-state lighting technologies. Combining olive leaf extracts with NiFe2O4 nanoparticles provided effective antioxidant and antibacterial activity by reducing and stabilizing of nanoparticles. Moreover, all experimental results reveal new ideas for the design and optimization of multifunctional nanomaterials with higher sensitivity and pave the way for the production of new functional nanomaterials.

Pongamia pinnata seed extract-mediated green synthesis of silver nanoparticle loaded nanogel for estimation of their antipsoriatic properties.

This research describes the eco-friendly green synthesis of silver nanoparticles employing Pongamia pinnata seed extracts loaded with nanogel formulations (AgNPs CUD NG) to improve the retention, accumulation, and the penetration of AgNPs into the epidermal layer of psoriasis. AgNPs were synthesized using the Box-Behnken design. Optimized AgNPs and AgNPs CUD NG were physico-chemically evaluated using UV-vis spectroscopy, SEM, FT-IR, PXRD, viscosity, spreadability, and retention studies. It was also functionally assessed using an imiquimod-induced rat model. The entrapment efficiency of AgNPs revealed ~ 79.35%. Physico-chemical parameters announced the formation of AgNPs via surface plasmon resonance and interaction between O-H, C = O, and amide I carbonyl group of protein extract and AgNO3. Optimized AgNPs showed spherical NPs ~ 116nm with better physical stability and suitability for transdermal applications. AgNPs CUD NG revealed non-Newtonian, higher spreadability, and better extrudability, indicating its suitability for a transdermal route. AgNPs CUD NG enhanced the retention of AgNPs on the psoriatic skin compared to normal skin. Optimized formulations exhibit no irritation by the end of 72h, indicating formulation safety. AgNPs CUD NG at a dose of 1 FTU showed significant recovery from psoriasis with a PASI score of ~ 0.8 compared to NG base and marketed formulations. Results indicated that seed extract-assisted AgNPs in association with CUD-based NG formulations could be a promising nanocarrier for psoriasis and other skin disorders.

Biofabrication of TiO2 nanoparticles via Aspergillus niger DS22 supernatant: bioreactor optimization and multi-activity profiling

AbstractThe study presents a safe and eco-friendly green synthesis of titanium dioxide nanoparticles (TiO2 NPs) using Aspergillus niger DS22 (ON076463.1) cell-free filtrate, focusing on optimizing factors affecting nitrate reductase enzyme production within the framework TiO2 NP biosynthesis. Maximum enzyme activity was accomplished by growing A. niger DS22 in a modified MYGP medium at pH 6, 0.5% peptone, 0.15% yeast extract, 0.25% KNO3, 2% glucose, and 200 rpm for 4 days at 30 °C. Statistical optimization takes place, where a central composite design was employed for testing the reaction variables. The individual and interactive effects of process variables lead to optimal biosynthesis conditions with 10−4 M (K2TiF6) concentration, for 96 h, 28 °C, pH 9, and Ti+4 salt solution:filtrate ratio (10%, v/v). Kinetic conversion rates in 1-L shake flask and 10-L stirred tank bioreactor were calculated and compared. Current findings revealed that the yield coefficient of biomass dry weight (Yx/s) and the yield coefficient of TiO2 NP dry weight (Y pn/s) in the bioreactor exceed those of the shake flask (0.85 g/L and 0.51 g/L; 0.04 g/L and 0.11 g/L, respectively). TiO2 NPs showed anticancer activities with high biocompatibility (at 1000 µg/mL) against MCF-7 and HepG-2 cell lines, with 97.35% and 97.71% cytotoxicity, respectively. TiO2 NPs had a moderate antioxidant activity of 57.8% recorded by DPPH assay. Moreover, TiO2 NPs had anticoagulant activities and decolorization efficiency for methyl orange dye. The current study paves the way for maximizing TiO2 NP production, which can be used in industrial and medical sectors. Graphical Abstract

Evaluation of the Effect of Different Extraction Temperatures on the Synthesis of Silver Nanoparticles from Ocimum basilicum (Basil) Plant

The eco-friendly green synthesis of silver nanoparticles (AgNPs) using Ocimum basilicum (basil) extract at varying extraction temperatures (40°C, 60°C, 80°C, 100°C) was investigated to determine the optimal conditions for nanoparticle formation. Analysis methods such UV-Vis spectrophotometry, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and TransmissionElectron Microscopy (TEM) confirmed the crystalline, spherical nature of AgNPs and identified phytochemicals acting as capping and reducing agents. Notably, the extraction temperature was found to influence both the DPPH radical scavenging activity and the structural properties of AgNPs. According to TEM analysis results, it was observed that high extraction temperatures increased the nanoparticle formation efficiency but created a wide size distribution. The crystallite sizes, calculated using the Scherrer equation, for AgNPs synthesized at different extraction temperatures, were determined to be 12.45 nm, 18.77 nm, 17.76 nm, and 16.03 nm, respectively. The hydrodynamic sizes of the AgNPs were found to range between 158.1 and 333.7 nm. The study highlights the critical role of extraction temperature in the synthesis process, suggesting 40°C as the optimal temperature for achieving efficient and environmentally friendly synthesis of AgNPs with enhanced biological activities.

Catalytic pyrolysis of fish waste oil using ZSM-5 catalyst for the production of renewable biofuel

This present study enlightens the eco-friendly green synthesis of ZSM-5 from natural clay montmorillonite, and its proper incorporation with ‘Ni’. Nickle (Ni) was wet impregnated onto HZSM-5 and the resulting catalyst was characterized by various techniques including XRD, BET, N2 Sorption Studies, TPD, SEM and TEM techniques. The SEM images revealed the uniform distribution of Ni over HZSM-5 zeolite catalyst and the XRD results indicated the undistorted crystalline structure of HZSM-5 even after impregnation of Ni. The latter part of the work concentrates on the strength of the catalyst in cracking oil derived from discarded fish parts. Discarded fish waste was pyrolyzed to obtain the fish oil, which was then used for cracking studies. The fish oil was efficiently converted (99% conversion) by Ni/ZSM5 (50 wt %) and yielded 70% liquid fractions, which formed gasoline (78.6%), kerosene (12.3%) and diesel (9.1%). The research is a complete parcel to examine the working potential of the produced biofuel in pre-existing engines. The quality of gasoline fraction was tested according to ASTM standards, which showed that the heating value was slightly lower compared to fossil gasoline. The torque and brake fuel consumption were also examined and it indicated that the fish oil derived gasoline fuel may need to be mixed with the commercial gasoline to optimize its performance.

Potentials of roots, stems, leaves, flowers, fruits, and seeds extract for the synthesis of silver nanoparticles.

Silver nanoparticles (AgNPs) have gained significant attention in various applications due to their unique properties that differ from bulk or macro-sized counterparts. In the advancement of nanotechnology, a reliable, non-toxic, and eco-friendly green synthesis has widely been developed as an alternative method for the production of AgNPs, overcoming limitations associated with the traditional physical and chemical methods. Green synthesis of AgNPs involves the utilization of biological sources including plant extracts with silver salt as the precursor. The potential of phytochemicals in plant extracts serves as a reducing/capping and stabilizing agent to aid in the bio-reduction of Ag+ ions into a stable nanoform, Ag0. This review provides insights into the potentials of various plant parts like root, stem, leaf, flower, fruit, and seed extracts that have been extensively reported for the synthesis of AgNPs.

Exploring Eco-Friendly Green Synthesis of Calcium Silicate and its Derivatives for Diverse Applications

Exploring Eco-Friendly Green Synthesis of Calcium Silicate and its Derivatives for Diverse Applications

Eco-friendly green synthesis of (Cu, Ce) dual-doped ZnO nanoparticles with Colocasia esculenta plant extract using microwave assisted technique for antioxidant and antibacterial activity

In the realm of biomedical applications, the inclusion of plant-derived components stands out as a critical consideration due to their non-toxic nature and antioxidant properties. In our research, we opt for Colocasia esculenta plant extract, utilizing microwave technology to create dually doped ZnO nanopowder with copper (Cu) and cerium (Ce). Authors employ XRD analysis to explore the structural attributes and crystallite size of the nanoparticles, which are found to be within the range of 16–19 nm. The surface and internal characteristics of these nanoparticles are precisely scrutinized using SEM-EDS and TEM characterization techniques. Additionally, ultraviolet-visible spectroscopy is utilized to determine the forbidden energy gap of the samples, providing insights into their potential applications in UV-protected devices. The synthesized nanoparticles exhibit significant antibacterial and antioxidant properties, highlighting their adaptability for various biomedical uses.

Green synthesis and optimization of iron oxide nanoparticles as MRI contrast agent

Iron nanoparticles (FeNPs) derived from herbal plants are being explored as potential magnetic resonance imaging (MRI) contrast agents due to their biocompatibility and ability to perform targeted drug delivery. For the first time, the usage of various novel combinations of leaf extracts such as those of Azadirachta indica and Piper betle and extracts of two other Ayurvedic herbs – namely, Asparagus racemosus and Symplocos – was attempted for eco-friendly green synthesis of FeNPs. The nanoparticles were coated onto nanofibers made from a banana pseudo-stem (FENPs-NF) to enhance their biocompatibility. The synthesis process was optimized using response surface methodology, and techniques such as ultraviolet–visible (UV–Vis) spectroscopy, vibrating-sample magnetometry, atomic absorption spectroscopy (AAS), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectroscopy (FT-IR) were used for characterization. Hemolytic and immune cell assays, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and MRI analysis were carried out. A peak at 325 nm observed in UV–Vis spectroscopy, AAS, FE-SEM, EDX and FT-IR proved the presence of FeNPs. Hemolytic and immune cell assays indicated biocompatibility, and the MTT assay (MCF-7) showed inhibition at 250 μg/ml. FeNPs and FeNPs-NF showed a good signal loss in MRI analysis at 1.5 T, proving their contrast agent nature. Thus, FeNPs synthesized from herbal plant sources may open a new door for potential application in the biomedical field as a chemical-free and biocompatible MRI contrast agent.

Cerric ammonium nitrate catalyzed eco-friendly green synthesis of chitosan Schiff base using PEG-400 as an anticancer agent against gastric cancer cells via inhibiting EGFR

The present study was conducted to scrutinize the pharmacological effect of oxazole-embedded Chitosan as an anticancer agent against gastric cancer cells. This compound was synthesized using the classical Schiff base reaction but utilizing the novel green chemical process where cerric ammonium nitrate (CAN) was used as a catalyst in the PEG-400 as solvent media. The target compound was obtained with an excellent yield at the catalyst loading of 5% CAN concentration in 15 min. The Kinase-Glo Plus luminescence kinase assay kit was used to determine the EGFR inhibitory activity of compound 1 where it showed potent activity with IC50 of 2.14 µM. Its effect was also determined on the cellular viability of the Human gastric cancer cell line (SGC7901), liver cancer cell line (HepG2), and lung cancer cell line (A549), where it exhibits potent activity against SGC7901. The compound further showed the concentration-dependent inhibitory effect on migration and invasion of SGC7901. In RT-qPCR analysis, the compound showed induction of apoptosis of SGC7901 cells possibly by restoring the expression of Bcl-2 and Bax near to normal, and inhibition of the mRNA expression of EGFR in a concentration-dependent manner. KEY WORDS: Schiff base, Chitosan, EGFR, mRNA, apoptosis, Bcl-2 Bull. Chem. Soc. Ethiop. 2024, 38(4), 1091-1101. DOI: https://dx.doi.org/10.4314/bcse.v38i4.22

Eco-friendly green synthesis of N‑pyrazole amino chitosan using PEG-400 as an anticancer agent against gastric cancer cells via inhibiting EGFR.

The present study was conducted to develop a green process that provides access to the development of Schiff base derivatives of chitosan with the heterocyclic moiety as a novel class of anti-gastric cancer agent. In the present study, we have synthesized these derivatives by reacting various pyrazoles with chitosan using CAN in PEG400. The compounds were synthesized in 20min in excellent yield by using CAN at 5% in PEG400 at 80°C in the shortest reaction time of 20min. The PEG400 could be efficiently recycled for the three consecutive runs. The developed compounds were tested for EGFR-TK inhibition using a Kinase-Glo Plus luminescence kinase assay kit where they exhibited significant activity revealing compound 2d as the most potent analog, while other compounds showed mild to moderate inhibitory activity. MTT assay was conducted to determine the effect of the three most potent EGFR inhibitors (2b, 2c, and 2d) on the proliferation of gastric cancer cells (SGC-7901). The results showed compound 2d as the most potent anticancer agent against SGC7901 cells. The effect of compound 2d was also quantified on the apoptosis and cell phase of SGC7901 cells using flow cytometry assay at various concentrations ranging from 0, 10, 20, and 30µM. Results suggest that compound 2d showed significant inhibition of SGC-7901 by inducing apoptosis and arresting G0/G1 cell phase. The western blot analysis also revealed that compound 2d significantly inhibited the overexpression of EGFR in SGC-7901 cells. The study successfully demonstrated the development of N‑pyrazole amino chitosan as a novel class of agent against gastric cancer via inhibition of EGFR.

Eco-friendly green synthesis of AgNPs from Elaeocarpus serratus fruit extract: potential to antibacterial, antioxidant, cytotoxic effects of colon cancerous cells (HT-29) and its toxicity assessments of marine microcrustacean Artemia nauplii.

The present work demonstrated the green synthesis and characterization of silver nanoparticles (AgNPs) utilizing Elaeocarpus serratus fruit extract. The study examined the effectiveness of phytocompounds in fruit extract in reducing Ag+ to Ag° ions. The water-soluble biobased substance production from silver ions to AgNPs in 45min at room temperature. Surface plasmon resonance (SPR) peak was seen in the UV-visible absorption spectrum of the biologically altered response mixture. Examination with X-ray diffraction (XRD) showed that AgNPs are strong and have a face-centered cubic shape. Scanning electron microscope (SEM) investigation proved the production of AgNPs in a cuboidal shape. The AgNPs demonstrated remarkable antibacterial activity and a potent capacity to neutralize DPPH (2,2-Diphenyl-1-picrylhydrazyl) radicals. The highest growth inhibition was found for E. serratus against S. dysenteriae (18.5 ± 1.0mm) and S. aureus (18 ± 1.2mm). These nanoparticles exhibited robust antiradical efficacy even at low concentrations. The AgNPs additionally exhibited cytotoxic effects on (HT-29) human colon adenocarcinoma cancer cells. The MTT assay (3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) indicated an inhibitory concentration (IC50) value of 49.1 ± 2.33µg/mL for AgNPs, contrasting with the untreated cells of the negative control. The biotoxicity assessment using A. salina displayed mortality rates ranging from 8 to 69.33%, attributable to the E. serratus synthesized AgNPs. In our results concluded that simply first-hand information on that E. serattus fruit extract synthesized AgNPs were efficiently synthesized without the addition of any hazardous substances, and that they may be a strong antibacterial, antioxidant, and potential cytotoxic effects for the treatment of colon carcinoma cell lines.

Ginger (Zingiber officinale)-Mediated Green Synthesis of Silver-Doped Tin Oxide Nanoparticles and Evaluation of Its Antimicrobial Activity.

Green synthesis of nanoparticles using plant extract is a novel development that has gained significant attention because of its low cost, nontoxicity, and environmental friendliness. In the present study, silver-doped stannic oxide (Ag-doped SnO2) nanoparticle was synthesized by an eco-friendly green synthesis method. The synthesized samples were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-vis), X-ray diffraction (XRD), and their antimicrobial activities were assessed against two bacteria Escherichia coli (E. coli) and Staphylococcus aureus (S. aurus) and two fungi Fusarium oxysporum (F. oxysporum) and Fusarium graminearum (F. graminearum) by using the disk diffusion method. Ag-doped SnO2 nanoparticles show a strong and broad absorption from UV-vis spectra when compared to pure SnO2 nanoparticles. FTIR spectral analysis revealed that the peak at 505.69 cm-1 was assigned to Sn-O and O-Sn-O stretching vibration of SnO2 nanoparticles. XRD analysis confirmed the formation of a tetragonal rutile structure with average particle size ranging from 10 to 17 nm. The antimicrobial result indicates that the Ag-doped SnO2 revealed significant antimicrobial activity against both bacterial and fungi strains with the zone of inhibition of 29 ± 0.54, 27 ± 0.05, 17 ± 0.05, and 15 ± 0.05 mm for S. aureus, E. coli, F. oxysporum , and F. graminearum, respectively. Thus, the studies suggested that Ag-doped SnO2 nanoparticles exhibit good activity against both Gram-negative and Gram-positive bacteria and fungi. This is because doping SnO2 nanoparticles with metallic elements such as Ag has been used to enhance their performance, confirming them as a good candidate for antimicrobial agents and the development of future therapeutic agents.

EVALUATING THE PRODUCTION POTENTIAL OF SIX (6) COMBRETUM SPECIES IN THE BIOMIMETIC SYNTHESIS OF SILVER NANOPARTICLES

Existing research has shown that plants are best suited for the ecofriendly green synthesis of nanoparticles. This study reported novel findings on the biomimetic synthesis of silver nanoparticles using the aqueous leaf extract of six medicinal plant species in the genus, Combretum (C. paniculatum, C. dolichopetalum, C. platypterum, C racemosum, C. bauchiense, and C. demeusei). It was concerned with the characterization, phytochemical screening, antimicrobial and cytological evaluation of the synthesized silver nanoparticles (AgNPs). The novelty of this study lies in the creation of a nanoparticle production index (NPPI) of the species based on their crystalline sizes (in nm) and yield (in mg/l) of AgNPs. This NPPI can be defined as a measure of the quantity of particles produced with respect to the experimental species. The study also investigated whether these species would produce similar results since they belong to the same genus. It was observed that the smaller the size of the nanoparticles, the higher the production index. The highest production index was observed in C. paniculatum (18.75 nm, 144. 6 mg/l), and the least in C. demeusei (0 nm, 6.3 mg/l). The AgNPs were characterized using various standard analytical techniques. The X-ray diffraction analysis indicated that the species showed 2 theta values in the 40° range, all corresponding to miller indices of (200). The synthesized AgNPs showed varying but significant antimicrobial activities. Also, majority of the species showed a high NPPI. The study heralds a system, “phytonanotaxonomy”, the classification of plants of the same taxa based on their NPPI.

Green synthesis of MnO2 nanoparticles from Psidium guajava leaf extract: Morphological characterization, photocatalytic and DNA/BSA interaction studies

In this work, a simple, efficient and eco-friendly green synthesis of manganese dioxide nanoparticles (MnO2NPs) by Psidium guajava leaf extract was described. Fourier-Transform infrared spectra results revealed that involvement of the plant extract functional groups in the formation of MnO2NPs. The UV–vis absorption spectra of the synthesized MnO2NPs exhibited absorption peaks at 374 nm, which were attributed to the band gap of the MnO2NPs. Crystal phase identification of the MnO2NPs were characterized by X-ray diffraction analysis and the formation of crystalline MnO2NPs have been confirmed. Furthermore, scanning electron microscopy analysis showed that the synthesized MnO2NPs have a spherical in shape. Interestingly, the prepared green synthesized MnO2NPs showed catalytic degradation activity for malachite green dye. Malachite green's photocatalytic degradation was detected spectrophotometrically in the wavelength range of 250–900 nm, and it was discovered to have a photodegradation efficiency of 75.5 % within 90 min when exposed to solar radiation. Green synthesized MnO2NPs are responsible for this higher activity. An interaction between synthesized NPs and biomolecules, including CT-DNA and BSA was also evaluated. The spectrophotometric and Fluoro spectroscopic analyses indicate a gradual reduction in peak intensities and shifts in wavelengths, indicating binding and affinity between the NPs and the biomolecules.