Synthesis Of Metal Nanoparticles Research Articles

Antibacterial activity of silver and gold nanoparticles that have been synthesized by curcumin

The green synthesis of metal nanoparticles with curcumin which is a compound with antibiotic effects, was considered for the synthesis of metal nanoparticles. Gold and silver nanoparticles were synthesized with an average diameter of 19.8 ± 6.2 nm and 29.8 ± 6.4 nm respectively. Both particles represent stability in the physiological environment and after a series of washing procedures to remove unreacted precursors. The antimicrobial efficacy of the synthesized nanoparticles was investigated in different techniques such as disk diffusion, agar well diffusion, minimum inhibitory concentration, and minimum bactericidal concentration tests. The results of both curcumin-coated metal nanoparticles in the disk diffusion test were negative. However, in the agar dilution and MIC tests of antibacterial effect of both nanoparticles on the tested bacteria was observed. The silver nanoparticles had an inhibitory effect on all selected bacteria in the agar dilution (8-256 µg/ml). However, gold nanoparticles had a lower inhibitory effect on the growth of some of the selected bacteria (64-512 µg/ml). In conclusion, silver nanoparticles were more effective than gold nanoparticles in most of the investigated methods.

Green synthesis of copper oxide nanoparticles using Simarouba glauca leaf extract, characterization and screening for their biological applications

The biological synthesis of metallic nanoparticles using plants has received a lot of attention because of their ability to decrease metallic ions by using the phytochemicals in them. The current study emphasizes the green synthesis of copper oxide nanoparticles (CuO NPs) with Simarouba glauca leaf extract. The synthesis of CuO NPs was characterized using UV-vis spectrophotometry, FTIR indicated the presence of different metabolites involved in the formation of nanoparticles, XRD showed the crystalline nature, SEM images indicated the rod shaped CuO NPs with the average size from 190 to 265 nm, EDS and mapping analysis showed the formation of CuO NPs with purity, and TEM analysis indicated the agglomerated and rod shaped CuO NPs. The average size of the nanoparticle was found to be 85 nm with zeta potential of −5.2 mV. TGA and DSC were performed to know the stability of the nanoparticle. Further, CuO NPs were assessed for their applications like antioxidant, antimicrobial properties. The anti-angiogenic, in vitro cell viability assay was performed using NPs against HCT-116, IC50 value to be 17.48 ± 0.6 µg/mL and HeLa cell lines, IC50 values to be 20.21 ± 0.33 µg/mL. The anti-ROS properties for both cell lines were assessed using histogram.

Chemical fingerprinting, antimicrobial, antioxidant, anti‐inflammatory, and anticancer potential of greenly synthesized silver nanoparticles from pistachio (Pistacia vera) nuts and senna (Cassia angustifolia Vahl.) leaves

AbstractThere is a growing interest in standardizing the biocompatible, cost‐effective, and eco‐friendly manufacturing techniques for metallic nanostructures due to their widespread applications in the industrial and medical sectors. In recent decades, green synthesis has been proven as the most suitable technique for synthesizing metal nanoparticles. The present research study investigates the use of Cassia angustifolia (senna) leaves and Pistacia vera (Pistachio) nuts to prepare crude aqueous extracts, ethanolic extracts, and biogenic silver nanoparticles (AgNPs). The prepared aqueous extracts were used as reducing, stabilizing, and capping agents for the production of silver nanoparticles. These AgNPs were characterized by scanning electron microscopy (SEM), Fourier‐transform infrared spectroscopy (FTIR), and ultraviolet–visible (UV–Vis) spectroscopy. The outcomes validated the formation of stable AgNPs with bioactive functional components. In vitro antibacterial, anticancer, anti‐inflammatory, and antioxidant potentials were assessed by Kirby–Bauer disk diffusion test, MIC test, MBC test, MTT assay, BSA denaturation inhibition assay, and DPPH antioxidant assay, respectively. Results confirmed that the tested plant extract possesses a variety of bioactive compounds with various biological activities and is therapeutically effective. These findings verified that C. angustifolia and P. vera are promising bioresources for the synthesis of therapeutic extracts and nanostructures with commendable therapeutic potency.

Generalized Synthesis of Highly-Dispersed, Ultrafine Transition Metal Nanoparticles on Silica Spheres for Enhanced Optical Absorption.

Robust synthesis of ultrafine metal nanoparticles (ufMNPs) below 5nm with clean surfaces and strong optical absorption in the visible spectral range is challenging due to their instability originating from large surface-to-volume ratios. This work reports a general strategy involving two sequential steps: i) loading metal precursor ions onto the surface of silica nanospheres (SiOx NSs) by forming a uniform coating of metal oxyhydroxide [MOy(OH)z] through preferred surface acid-base reactions and ii) thermally reducing MOy(OH)z in forming gas at elevated temperatures to form ufMNPs evenly dispersed on the surface of SiOx NSs. The capability of this synthesis strategy is verified by loading ufMNPs of various transition metals and bimetallic combinations onto the SiOx NSs. The ufMNPs exhibit strong optical absorption enhanced by the optical scattering resonances in the SiOx NSs, which generate intense electric fields near the surface of the SiOx NSs. The SiOx NSs also support stabilizing the ufMNPs, which do not need additional organic capping reagents. The successful synthesis of SiOx-NS-supported ufMNPs with clean surfaces and enhanced optical absorption is promising for exploring the photocatalytic properties of ufMNPs.

Phyco-synthesis of silver nanoparticles by environmentally safe approach and their applications

In recent years, there has been an increasing interest in the green synthesis of metallic nanoparticles, mostly because of the evident limitations associated with chemical and physical methods. Green synthesis, commonly referred to as "biogenic synthesis," is seen as an alternative approach to produce AgNPs (silver nanoparticles). The current work focuses on the use of Asterarcys sp. (microalga) for biological reduction of AgNO3 to produce AgNPs. The optimal parameters for the reduction of AgNPs were determined as molarity of 3 mM for AgNO3 and an incubation duration of 24 h at pH 9, using a 20:80 ratio of algal extract to AgNO3. The biosynthesized Ast-AgNPs were characterised using ultraviolet–visible spectroscopy (UV–Vis), zeta potential, scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and high-resolution transmission electron microscopy (HR-TEM) with selected area electron diffraction (SAED) patterns. The nanoparticles exhibited their highest absorption in the UV–visible spectra at 425 nm. The X-ray diffraction (XRD) investigation indicated the presence of characteristic peaks at certain angles: 38.30° (1 1 1), 44.40° (2 0 0), 64.64° (2 2 0), and 77.59° (3 1 1) according to the JCPDS file No. 04-0783. Based on SEM and TEM, the Ast-AgNPs had an average size of 35 nm and 52 nm, respectively. The zeta potential was determined to be − 20.8 mV, indicating their stability. The highest antibacterial effectiveness is shown against Staphylococcus aureus, with a zone of inhibition of 25.66 ± 1.52 mm at 250 μL/mL conc. of Ast-AgNPs. Likewise, Ast-AgNPs significantly suppressed the growth of Fusarium sp. and Curvularia sp. by 78.22% and 85.05%, respectively, at 150 μL/mL conc. of Ast-AgNPs. In addition, the Ast-AgNPs exhibited significant photocatalytic activity in degrading methylene blue (MB), achieving an 88.59% degradation in 120 min, revealing multiple downstream applications of Ast-AgNPs.

Phytosynthesis of silver nanoparticles using aqueous sandalwood (Santalum album L.) leaf extract: Divergent effects of SW-AgNPs on proliferating plant and cancer cells.

The biogenic approach for the synthesis of metal nanoparticles provides an efficient eco-friendly alternative to chemical synthesis. This study presents a novel route for the biosynthesis of silver nanoparticles using aqueous sandalwood (SW) leaf extract as a source of reducing and capping agents under mild, room temperature synthesis conditions. The bioreduction of Ag+ to Ago nanoparticles (SW-AgNPs) was accompanied by the appearance of brown color, with surface plasmon resonance peak at 340-360 nm. SEM, TEM and AFM imaging confirm SW-AgNP's spherical shape with size range of 10-32 nm. DLS indicates a hydrodynamic size of 49.53 nm with predominant negative Zeta potential, which can contribute to the stability of the nanoparticles. FTIR analysis indicates involvement of sandalwood leaf derived polyphenols, proteins and lipids in the reduction and capping of SW-AgNPs. XRD determines the face-centered-cubic crystalline structure of SW-AgNPs, which is a key factor affecting biological functions of nanoparticles. This study is novel in using cell culture methodologies to evaluate effects of SW-AgNPs on proliferating cells originating from plants and human cancer. Exposure of groundnut calli cells to SW-AgNPs, resulted in enhanced proliferation leading to over 70% higher calli biomass over control, enhanced defense enzyme activities, and secretion of metabolites implicated in biotic stress resistance (Crotonyl isothiocyanate, Butyrolactone, 2-Hydroxy-gamma-butyrolactone, Maltol) and plant cell proliferation (dl-Threitol). MTT and NRU were performed to determine the cytotoxicity of nanoparticles on human cervical cancer cells. SW-AgNPs specifically inhibited cervical cell lines SiHa (IC50-2.65 ppm) and CaSki (IC50-9.49 ppm), indicating potential use in cancer treatment. The opposing effect of SW-AgNPs on cell proliferation of plant calli (enhanced cell proliferation) and human cancer cell lines (inhibition) are both beneficial and point to potential safe application of SW-AgNPs in plant cell culture, agriculture and in cancer treatment.

Flow synthesis of silver nanoparticles using water in supercritical CO2 emulsion

Rapid and continuous synthesis of metal nanoparticles using green solvent system is still a serious challenge for both fundamental and practical research. In this work, we report a new flow process using water in supercritical CO2 (w/scCO2) emulsion and applied it to the synthesis of silver nanoparticles (AgNPs). To investigate the performance of our system, AgNPs were synthesized by batch, flow and w/scCO2 emulsion flow system at 40 ºC while using AgNO3, NaBH(OAc)3, trisodium citrate and Aerosol-OT as precursor, reducer, stabilizer and emulsifier. As a result, we demonstrated that water droplets in w/scCO2 emulsion significantly contribute to a rise in the size controllability and productivity (product yield). Additionally, w/scCO2 emulsion flow process allowed the control of mean size from 4.0 to 36.6 nm and yield from 25% to 65% by changing the CO2 pressure and Aerosol-OT concentration. Furthermore, synthesized AgNPs successfully gave citrate-modified surface with high zeta potential of –54 mV and the transparent water dispersion with unimodal size distribution, showing promising potential to allow various practical applications.

Efficient removal of environmental pollutants by green synthesized metal nanoparticles of Clitoria ternatea

Prevention and management of water pollution are becoming a great challenge in the present scenario. Different conventional methods like carbon adsorption, ion exchange, chemical precipitation, evaporation, and biological treatments remove water pollutants. Nowadays, the requirement for effective, non-toxic and safe waste management strategies is very high. Nanomaterials have been explored in various fields due to their unique characteristics. Green synthesis of nanomaterial is becoming more popular due to their safety, non-toxicity, and ease of scale-up technology. Metal nanoparticles can be synthesized using a green synthesis method using biological sources provided by eco-friendly, non-hazardous nanomaterials with superior properties to bulk metals. Hence, this study has designed a green synthesis of magnetic (cobalt oxide) and noble (gold) nanoparticles from the fresh flowers of Clitoria ternatea. The flavonoids and polyphenols in the extract decreased the energy band gap of cobalt oxide and gold nanoparticles; hence, the capping of the natural constituents in Clitoria ternatea helped form stable metal nanoparticles. The cobalt oxide and gold nanoparticles are evaluated for their potential for eliminating organic pollutants from industrial effluent. The novelty of this present work represents the application of cobalt oxide nanoparticles in the removal of organic pollutants and a comparative study of the catalytic behaviour of both metal nanoparticles. The degradation of bromophenol blue, bromocresol green, and 4–nitrophenol in the presence of gold nanoparticles was completed in 120, 45, and 20 min with rate constants of 3.7 × 10−3/min, 6.9 × 10−3/min, and 16.5 × 10−3/min, respectively. Similarly, the photocatalysis of bromophenol blue, bromocresol green, and 4–nitrophenol in the presence of cobalt oxide nanoparticles was achieved in 60, 90, and 40 min with rate constants of 2.3 × 10−3/min, 1.8 × 10−3/min, and 1.7 × 10−3/min, respectively. The coefficient of correlation (R2) values justify that the degradation of organic pollutants follows first-order kinetics. The significance of the study is to develop green nanomaterials that can be used efficiently to remove organic pollutants in wastewater using a cost-effective method with minimal toxicity to aquatic animals. It has proved to be useful in environmental pollution management.

Growth Process of Fe-O Nanoclusters with Different Sizes Biosynthesized by Protein Nanocages.

All protein-directed syntheses of metal nanoclusters (NCs) and nanoparticles (NPs) have attracted considerable attention because protein scaffolds provide a unique metal coordination environment and can adjust the shape and morphology of NCs and NPs. However, the detailed formation mechanisms of NCs or NPs directed by protein templates remain unclear. In this study, by taking advantage of the ferritin nanocage as a biotemplate to monitor the growth of Fe-O NCs as a function of time, we synthesized a series of iron NCs with different sizes and shapes and subsequently solved their corresponding three-dimensional atomic-scale structures by X-ray protein crystallography and cryo-electron microscopy. The time-dependent structure analyses revealed the growth process of these Fe-O NCs with the 4-fold channel of ferritin as nucleation sites. To our knowledge, the newly biosynthesized Fe35O23Glu12 represents the largest Fe-O NCs with a definite atomic structure. This study contributes to our understanding of the formation mechanism of iron NCs and provides an effective method for metal NC synthesis.

Facile green synthesis of silver nanoparticles: Relevance in localized surface plasmon resonance and molecular imprinted polymer sensor for detection of Tetrabromobisphenol A in electronic waste

The present study demonstrates evocatively the interest in prioritizing an environmental friendly approach. Green synthesis of metallic nano-particles is carried out, which is further incorporated with a technique known as Molecular Imprinted Polymers (MIP) to develop a highly sensitive cuvette-based localized surface plasmon resonance (LSPR) probe for the selective detection of a Tetrabromobisphenol-A (TBBPA). TBBPA is a hazardous phenolic compound, mostly found in electronic waste (E-waste), that is abundant on earth. We have fabricated an LSPR probe with the help of a transparent glass substrate. A layer of Silver nanoparticles has been decorated over the glass substrate which further has an MIP overlayer on it. The glass slide dimensions are so chosen that it can fit inside the cuvette along its one side. The absorbance spectra are then recorded for a concentration range of 0–500 ng/ml of TBBPA. The sensitivity and limit of detection of the proposed sensor have been found to be 0.228 nm/ng ml−1 and 4.68 ng/ml respectively. Also, the probe showed quite promising recovery percentage greater than 85 % in real samples. Hence, with the findings and outcomes our fabricated probe can be represented as a potential candidate in selective detection of TBBPA along with the benefits of low cost of fabrication, portable, and real-time monitoring.

Green synthesis of CdS/flaxseed mucilage nanocomposite films using gamma irradiation for packaging applications

Abstract The most common ways to produce nanoparticles are through chemical and physical processes, which can be expensive and environmentally hazardous. Using plant extracts (green synthesis) as reducing and capping agents is a simple, cost-effective, and environmentally friendly method of lowering the usage of dangerous chemicals in the synthesis of metal nanoparticles. This study covers the environmentally friendly synthesis of cadmium sulphide nanoparticles (CdS NPs) using a blend of flaxseed extracts (FM), polyvinyl alcohol (PVA), and chitosan (Cs). The composites are then exposed to gamma irradiation at doses of 20 kGy and 40 kGy. UV–VIS absorption spectroscopy, SEM, HRTEM, EDX, and FTIR were used to analyse the produced nanocomposite films. UV–Vis absorption spectra showed considerable surface Plasmon resonance (SPR) bands at 396–440 nm, indicating that CdS NPs had been successfully synthesized. A progressive red shift in wavelength was noted, along with the broadening of the absorption band as the irradiation dose increased. Transmission electron microscopy pictures revealed that the generated CdS nanostructures were dispersed as spherical nanoparticles with remarkable structural homogeneity. Tensile strength and elongation measurements of the films revealed that the inclusion of CdS NPs improved their mechanical properties. The addition of CdS NPs to the current blends limits biodegradation in soil. Thermal gravimetric analysis findings showed that CdS NPs included in FM/PVA films had improved thermal stability. The antimicrobial activities of the tested films were performed against Staphylococcus aureus, Escherichia coli, and Candida albicans. The results revealed that all of the films exhibited more antibacterial activity against S. aureus than the two others, with the highest activity observed in nanocomposites with a high concentration of CdS.

Green synthesis, characterization and applications of Phyllanthus emblica fruit extract mediated chromium oxide nanoparticles

The green synthesis of metallic nanoparticles is attributable towards diverse applications in various fields, recently. In this research, we report simple and eco-friendly synthesis of chromium oxide (Cr2O3) nanoparticles using the fruit extract of Phyllanthus emblica as a reducing and capping agent. The absorbance peaks at 350 nm and 450 nm validated the nanoparticle formation in UV–visible spectrum. FTIR spectrum revealed the nature of functional groups. The crystalline properties of nanoparticles were ascertained by XRD analysis. EDX spectrum corroborated the elemental composition of nanoparticles in which chromium and oxygen constituted 68% of total weight. SEM images demonstrated agglomeration of nanoparticles resulting in the formation of large irregularly shaped flakes. Cr2O3 nanoparticles demonstrated excellent antimicrobial properties against 11 bacterial isolates and 1 fungal isolate. The largest inhibition zone (53 mm) was measured against A. baumannii while the smallest inhibition zone (26 mm) was recorded against S. aureus. Minimum inhibitory concentration (MIC) values were < 1 µg/ml for all microbes. However, the synthesized nanoparticles did not reveal synergism with any of the selected antibiotics (FICI values > 1). Nanoparticles possessed potent anti-biofilm powers with maximum (77%) inhibition of E. coli biofilms and minimum (45%) inhibition of S. enterica biofilms. Photocatalytic activity of Cr2O3 nanoparticles was evaluated to determine their efficacy in environmental bioremediation. Outcomes demonstrated degradation of methyl red (84%) but not of methylene blue dye. Furthermore, the Cr2O3 nanoparticles displayed considerable antioxidant (43%) as well as anti-inflammatory (44%) potentials. Hence, the present study accounts for the versatile applications of P. emblica-mediated Cr2O3 nanoparticles which could be pursued for future biomedical and environmental applications.Graphical

Mechanism behind the Controlled Generation of Liquid Metal Nanoparticles by Mechanical Agitation.

The size-controlled synthesis of liquid metal nanoparticles is necessary in a variety of applications. Sonication is a common method for breaking down bulk liquid metals into small particles, yet the influence of critical factors such as liquid metal composition has remained elusive. Our study employs high-speed imaging to unravel the mechanism of liquid metal particle formation during mechanical agitation. Gallium-based liquid metals, with and without secondary metals of bismuth, indium, and tin, are analyzed to observe the effect of cavitation and surface eruption during sonication and particle release. The impact of the secondary metal inclusion is investigated on liquid metals' surface tension, solution turbidity, and size distribution of the generated particles. Our work evidences that there is an inverse relationship between the surface tension and the ability of liquid metals to be broken down by sonication. We show that even for 0.22 at. % of bismuth in gallium, the surface tension is significantly decreased from 558 to 417 mN/m (measured in Milli-Q water), resulting in an enhanced particle generation rate: 3.6 times increase in turbidity and ∼43% reduction in the size of particles for bismuth in gallium liquid alloy compared to liquid gallium for the same sonication duration. The effect of particles' size on the photocatalysis of the annealed particles is also presented to show the applicability of the process in a proof-of-concept demonstration. This work contributes to a broader understanding of the synthesis of nanoparticles, with controlled size and characteristics, via mechanical agitation of liquid metals for diverse applications.

Plant-Based Insecticides for Control of Aedes aegypti, Sitophilus zeamais and Nasutitermes corniger: A Review and Bibliometric Analysis

Insect pests can transmit diseases or affect the economy and their uncontrolled growth is intensified by human activity, which has affected ecosystems and interfered with trophic chains. Aedes aegypti L. transmits dengue, chikungunya, zika and yellow fever, while Sitophilus zeamais Motsch is a stored grain pest, and Nasutitermes corniger Motsch attacks trees and urban buildings. This work provides a review of the state of art and current trends, as well as a bibliometric analysis on the insecticidal activity of plant-based products against Ae. aegypti, S. zeamais and N. corniger. The review of literature data showed that plant insecticides comprise secondary metabolites and proteins that can impair the viability of embryos, larvae, pupae, and adults, as well as fertility and oviposition or feeding behavior of insects. Also, they tend to be more biodegradable and less harmful to non-target organisms compared to synthetic insecticides. The bibliometric analysis revealed the concentration of publications in tropical regions worldwide, where there is a strong occurrence of diseases transmitted by Ae. aegypti. These reports were far more numerous than those on N. corniger and S. zeamais. Furthermore, the synthesis of metallic nanoparticles from plant products has strongly emerged as a current trend.

Green synthesis of metal nanoparticles from Codium macroalgae for wastewater pollutants removal by adsorption

AbstractAlgae have adsorption properties and reducing agents due to their rich content. In this study, palladium nanoparticles (Pd NP), platinum nanoparticles (Pt NP), and iron oxide nanoparticles (Fe3O4 NP) were prepared from Codium macroalgae using green synthesis. The structure of the synthesized nanoparticles was elucidated by X‐ray diffractometry, Fourier transforms infrared spectroscopy, Brunauer–Emmett–Teller analysis, transmission electron microscopy, ultraviolet‐visible spectroscopy and scanning electron microscopy‐energy dispersive X‐ray spectrometry and their use as nanoadsorbents for the removal of pollutants from aqueous media was investigated in detail. Naproxen (NPX), an anti‐inflammatory drug, and the dyes methylene blue (MB) and cresol red (CR) were selected as pollutants for this study. Batch adsorption experiments were conducted using both real wastewater obtained from the Organised Industrial Zone of Isparta Province and synthetic water samples prepared with tap water from Burdur Province and pure water. Under optimum adsorption conditions, Pd NP showed significant efficiency in the real wastewater sample, with an adsorption capacity of 37.19 and 50.03 mg g–1 for CR and NPX, respectively, within 150 min. In comparison, Pt NP showed an adsorption capacity of 40.01 mg g–1 for MB within the same timeframe. These findings indicate that while Pd NP showed the highest adsorption capacity for both CR and NPX, Pt NP showed the highest adsorption capacity for MB. The Langmuir model and the pseudo‐second‐order equation were more suitable to describe the adsorption behavior of CR, MB, and NPX. In addition, studies on the desorption and reusability of the nanoadsorbents were carried out under the same optimum experimental conditions.

Green synthesis of metal nanoparticles and their applications in degradation of azo dye

Green synthesis of metal nanoparticles and their applications in degradation of azo dye

Passively Q-switched Er-doped fiber laser based on carbon-doped silver nanoparticles saturable absorber prepared using laser ablation method

In this work, we investigate the effect of carbon-doped silver nanoparticles on the Q-switched performance of erbium-doped fiber laser (EDFL). The carbon-doped silver nanoparticles were synthesized using a laser ablation method. The prepared nanoparticles were inserted between fiber ferrules using the adhesion process of the index-matched gel. Incorporating a saturable absorber inside the laser cavity initiates a stable Q-switched mechanism at 11.2 mW of threshold power. The measured results demonstrate that as the pump power of EDFL increases from 11.2 to 267 mW, the pulse repetition, and pulse width tuned from 21.33 to 95.2 kHz and 13.3–3.18 µs, respectively. At 267 mW of pump, the maximum average output power, pulse energy, and peak power were further measured to be 2.36 mW, 24.68 nJ, and 7.76 mW, respectively. Besides, the stability and threshold characteristics of EDFL based on carbon-doped silver nanoparticles were further explored. This study shows that the synthesis of metal nanoparticles using the laser ablation technique and their implementation as saturable absorber represents a promising avenue for advancing ultrafast laser technologies with improved stablility, efficiency, and tunability.

Bioinorganic metal nanoparticles and their potential applications as antimicrobial, antioxidant and catalytic agents: a review

Abstract This review article covers the biogenic synthesis of metal nanoparticles (MNPs) having definite shape and size while using extract obtained from different biological sources such as bacteria, fungi, algae and plants. These biological materials are composed of chloroplast, thylakoid, different types of enzymes extracted from different biogenic sources, different phytochemicals such as phenols, flavonoids, and citric acid having functional groups such as sulfate, carboxyl, amino, amide and hydroxyl groups. These functional groups and enzymes act as efficient reductants to convert metal ions into metal atoms and alternatively metal atoms combine to form MNPs while long hydrocarbon chains present in these bio-macromolecules act as cage to stabilize them for prolong time. Effect of nature of source extract, different reaction conditions such as extract amount, salt amount and solvent used during MNPs preparation process have been critically discussed here in detail. Use of synthesized bioinorganic NPs in various areas including their effectiveness in fighting against bacteria, viruses, fungi, cancer, inflammation, and their potential role in catalytic reduction of environmental harmful substances into friendly products has also been described in a clear and concise manner along with their future consideration.

Synthesis of multifunctional silver oxide, zinc oxide, copper oxide and gold nanoparticles for enhanced antibacterial activity against ESKAPE pathogens and antioxidant, anticancer activities using Momordica cymbalaria seed extract

Rising emergence in public health due to antibiotic-resistant of ESKAPE pathogens, diseases related to oxidative damage and cancer has driven the urgent need to develop potent therapeutics for resistant bacterial strains, free radical scavenging and cancer. The present study involves Momordica cymbalaria seed extracts mediated synthesis of metal nanoparticles and to evaluate its ameliorative potency against ESKAPE pathogens, free radicals and cancer cells. The study includes therapeutic approaches to target pathogenic biofilms relating phyto-therapeutics with nanotechnology. In the present investigation, we have synthesized four metal oxide nanoparticles of Silver, Zinc, Copper (Ag2O, ZnO and CuO), and Gold nanoparticles (Au NPs) using the seed extracts of M. cymbalaria. The synthesized nanoparticles were characterized by various biophysical techniques like X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) Field-Emission Scanning Electron Microscopy (FESEM) with energy-dispersive X-ray spectroscopy (EDX) and High-Resolution Transmission Electron Microscopy (HR-TEM) with Selected Area Electron Diffraction (SAED). Agar well diffusion methods, or Antimicrobial methods (MIC, MBC, and MBIC), DPPH/ABTS free radical scavenging assay, MTT/apoptotic studies and protein/DNA damage inhibition assays were performed to evaluate the antibacterial, anticancer and antioxidant activities. Crystalline properties of metal oxides NPs were established by XRD pattern and the presence of alcohol or phenol, ketone, and amine groups in M. cymbalaria seed was confirmed by FTIR analysis. That participates in the reduction of Ag+, Cu+, Zn+, and Au+ ions to NPs. All the nanoparticles showed dose-dependent antibacterial, anticancer and antioxidant activity. Protein and DNA oxidation inhibition assays demonstrated an efficient quenching effect of proxy radicals by all the NPs. Therefore, M. cymbalaria -mediated synthesis of metal NPs can be used as an alternative to toxic physical or chemically mediated synthesis that can be applied to develop multifunctional nanoparticles as efficient therapeutics.

Green Synthesis of Gold Nanoparticles Using Liquiritin and Other Phenolics from Glycyrrhiza glabra and Their Anti-Inflammatory Activity.

Phenolic compounds are the main phytochemical constituents of many higher plants. They play an important role in synthesizing metal nanoparticles using green technology due to their ability to reduce metal salts and stabilize them through physical interaction/conjugation to the metal surface. Six pure phenolic compounds were isolated from licorice (Glycyrrhiza glabra) and employed in synthesizing gold nanoparticles (AuNPs). The isolated compounds were identified as liquiritin (1), isoliquiritin (2), neoisoliquiritin (3), isoliquiritin apioside (4), liquiritin apioside (5), and glabridin (6). The synthesized AuNPs were characterized using UV, zeta sizer, HRTEM, and IR and tested for their stability in different biological media. The phenolic isolates and their corresponding synthesized NP conjugates were tested for their potential in vitro cytotoxicity. The anti-inflammatory effects were investigated in both normal and inflammation-induced settings, where inflammatory biomarkers were stimulated using lipopolysaccharides (LPSs) in the RAW 264.7 macrophage cell line. LPS, functioning as a mitogen, promotes cell growth by reducing apoptosis, potentially contributing to observed outcomes. Results indicated that all six pure phenolic isolates inhibited cell proliferation. The AuNP conjugates of all the phenolic isolates, except liquiritin apioside (5), inhibited cell viability. LPS initiates inflammatory markers by binding to cell receptors and setting off a cascade of events leading to inflammation. All the pure phenolic isolates, except isoliquiritin, neoisoliquiritin, and isoliquiritin apioside inhibited the inflammatory activity of RAW cells in vitro.