Green synthesis and characterization of silver nanoparticles from Moringa oleifera flower and assessment of antimicrobial and sensing properties

Green synthesis of silver nanoparticles by Conocarpus Lancifolius plant extract and their antimicrobial and anticancer activities

Due to drug addiction and the emergence of antibiotic resistance in pathogens, the disease load and medication intake have risen worldwide. The alternative treatment for drug-resistant infections is Nano formulation-based antimicrobial agents. The plant extract of Conocarpus Lancifolius fruits was used to synthesize silver nanoparticles in the current study, and it was further employed as an antimicrobial and anticancer agent. Nanoparticles have been characterized by UV-visible spectrometer revealed the notable peak of λmax = 410-442 nm, which confirms the reduction of silver ion to elemental silver nanoparticles, and the biological moieties in the synthesis were further confirmed by FTIR analysis. The stability and crystalline nature of materials were approved by XRD analysis and expected the size of the nanomaterials of 21 to 173 nm analyzed by a nanophox particle-size analyzer. In vitro, synthesized materials act as an antibacterial agent against Streptococcus pneumonia and Staphylococcus aureus. The inhibition zones of 18 and 24 mm have been estimated to be antibacterial activity against both bacteria. The potency of up to 100% of AgNPs for bacterial strains was incubated overnight at 60 μg/ml. Based on our results, biogenic AgNPs reveal significant activity against fungal pathogen Rhizopusus stolonifera and Aspergillus flavus that cause leading infectious diseases. Additionally, nanomaterials were biocompatible and demonstrated the potential anticancer activities against MDA MB-231 cells after 24-hour exposure.

Microwave assisted green synthesis of silver nanoparticles for optical, catalytic, biological and electrochemical applications

Plant-derived nanoparticles have multi-functionalities owing to their ecological origin and biocompatible nature. A novel and stable silver nanoparticle (AgNP) was reported here using Cyanthillium cinereum (C. cinereum) as a reducing as well as capping agent by rapid microwave-assisted green method. The synthesized nanoparticles revealed their crystalline and spherical nature with an average size of 19.25 ± 0.44 nm in HR-TEM analysis. The excitation of electrons from occupied d-bands to states above the Fermi level while employing photoluminescence studies of AgNP indicated their awesome optical properties. Rapid decomposition of dangerous organic dyes like methylene blue and fuchsine in the catalytic presence of AgNP was evidenced from simple UV-visible spectral analysis. In vitro antioxidant potential assessed by DPPH assay indicated an IC50 value of 40.80 ± 0.14 μg/mL for the new AgNP. A substantial control on the growth of pathogenic bacteria such as Staphylococcus aureus and Klebsiella pneumonia can be achieved by synthesized nanoparticles as demonstrated by the well diffusion method. AgNP was also functioned as a non-enzymatic electrochemical sensor with a sharp oxidation peak with peak potentials at 0.366 V and it has a wide application as a bio sensor in neurobiology especially in the detection of neurotransmitters like dopamine with high sensitivity.

Environmental photochemistry in Solanum trilobatum mediated plasmonic nanoparticles as a probe for the detection of Cd2+ ions in water

Nowadays world deals with a lot of environmental troubles out of which water pollution is very dangerous. Water gets contaminated by heavy metal ions is a universal problem which needs suitable consideration to keep up the quality of the water. It will be advantageous that an easy device can be detecting the concentration of heavy metal ions in water. Here, a contaminant, cadmium from industrial affluent into water is considered and focused. Gold nanoparticles (AuNPs) have been synthesized by Solanum trilobatum leaf extract and its applications of antifungal and sensing activity was reported here. The influences of different concentration of these reducing agent on the synthesis of AuNPs (G5 and G10) have been evaluated. The structural, optical, vibrational, morphological and compositional properties of the AuNPs were studied through XRD, UV-vis spectra, FTIR, HRTEM and EDAX analysis. The optical studies showed surface plasmon absorbance peak at 526 nm. It shows that the absorbance of the peak becomes narrow with a higher concentration of leaf extract. XRD results showed the average size of the AuNPs was 8 nm. It also confirmed the high crystallinity of nanoparticles. FTIR exposes that amine and carboxyl groups may be involved in the stabilization and reduction mechanism. TEM pictures of both G10 and G5 demonstrate merely spherical nanoparticles. This morphology control is taken place owing to the adsorbed amine and carboxyl groups onto the gold nanoparticles cap the particles and improve the stability. The presence of gold elements in the sample was identified with the help of EDAX. The sensitivity of the system towards various Cd²⁺ concentrations was measured as 0.058/mM for G5 and 0.095/mM for G10. The prepared nanoparticles produced highest zone of inhibition (ZOI) of 17.5 mm and 19 mm against human being pathogenic fungi Aspergillus Flavus and Candida albicans respectively. Here, small sized spherical nanoparticles showed good antifungal activity.

Green Synthesis of Metal and Metal Oxide Nanoparticles: Principles of Green Chemistry and Raw Materials

Increased request for metal and metal oxide nanoparticles nanoparticles has led to their large-scale production using high-energy methods with various toxic solvents. This cause environmental contamination, thus eco-friendly “green” synthesis methods has become necessary. An alternative way to synthesize metal nanoparticles includes using bioresources, such as plants and plant products, bacteria, fungi, yeast, algae, etc. “Green” synthesis has low toxicity, is safe for human health and environment compared to other methods, meaning it is the best approach for obtaining metal and metal oxide nanoparticles. This review reveals 12 principles of “green” chemistry and examples of biological components suitable for “green” synthesis, as well as modern scientific research of eco-friendly synthesis methods of magnetic and metal nanoparticles. Particularly, using extracts of green tea, fruits, roots, leaves, etc., to obtain Fe3O4 NPs. The various precursors as egg white (albumen), leaf and fruit extracts, etc., can be used for the „green” synthesis of spinel magnetic NPs. “Green” nanoparticles are being widely used as antimicrobials, photocatalysts and adsorbents. “Green” magnetic nanoparticles demonstrate low toxicity and high biocompatibility, which allows for their biomedical application, especially for targeted drug delivery, contrast imaging and magnetic hyperthermia applications. The synthesis of silver, gold, platinum and palladium nanoparticles using extracts from fungi, red algae, fruits, etc., has been described.

Antimicrobial resistance profile of Staphylococcus aureus and its in-vitro potential inhibition efficiency

BACKGROUND

Staphylococcus aureus infection is associated with hospitals and caused mortality in hospitalized patients. These biofilm-forming bacteria are associated with chronic infections in patients.

OBJECTIVES

To investigate the biofilm forming ability of multidrug resistant bacteria associated with hospital environment and analyze anti-biofilm compounds from the natural sources.

METHODS

The hospital wastewater sample was used for the isolation of drug resistant S. aureus strains. The biofilm producing ability was analyzed and the isolated S. aureus strains were tested for antibiotic susceptibility patterns against various antibiotics. To screen suitable antibacterial agent, essential oil was extracted from Teucrium polium by hydrodistillation method and the compounds were determined by GC-MS analysis. The antimicrobial potential of essential oil was studied against S. aureus strains by disc diffusion method and biofilm inhibition property of essential oil was analyzed. The synergistic activity of essential oil was also analyzed.

RESULTS

A total of 13 S. aureus strains were isolated and almost all bacterial strains showed biofilm forming ability. Most of the isolated S. aureus strains showed resistance to ampicillin, cefoxitin, ciprofloxacin, erythromycin, gentamicin, chloramphenicol and vancomycin. The extracted essential oil showed pale yellow in colour with pleasant odour and the yield was about 0.9%. Twenty-two compounds were detected in GC-MS analysis which shared about 96% of the total determined chemical composition. The major compounds determined were α-pinene (5.3%), linalool (16.2%), caryophyllene (10.04%), germacrene D (37.2%), and β-eudesmol (6.1%). The extracted essential oil showed antibacterial activity and the zone of inhibition varied from 15 ± 1 to 21 ± 2 mm against S. aureus strains. The essential oil showed antibiofilm activity and synergistic activity against S. aureus strains.

CONCLUSIONS

This study analyzed biofilm forming ability of drug resistant S. aureus strains isolated from the hospital wastewater. The isolated bacterial strains showed resistance against various tested antibiotics. The essential oil extracted from T. polium showed antibacterial and anti-biofilm activity.

Functionalization of gold nanoparticles by β-cyclodextrin as a probe for the detection of heavy metals in water and photocatalytic degradation of textile dye

Gold nanoparticles (AuNPs) and AuNPs functionalized by β-cyclodextrin (β-CD/AuNPs) were prepared successfully through chemical reduction method. The structural, morphological, optical, compositional and vibrational studies for the AuNPs and β-CD/AuNPs were carried out. Functionalization of AuNPs by β-CD was confirmed with FT-IR results. The UV-visible absorption spectra exhibit a red-shift with decreasing average particle size. This sustains the enhancement in surface area (SA) to volume (V) ratio that is one of the peculiar characteristics of nanoparticles. TEM results show that β-CD/AuNPs formed were monodispersed and self assembled. Also it shows a decrease in average particle size and improved distribution. The use of β-CD in the synthesis of AuNPs are revealed not only create uniform small sized nanoparticles but these water soluble nanoparticles have very good antibacterial action by inhibiting the growth of bacteria commonly found in water and sensing activity for sensing the concentration of toxic metals in water. The sensitivity of the system towards copper (Cu) concentration was found as 1.788/mM for β-CD/AuNPs and 1.333/mM for AuNPs. The photocatalytic action of the obtained nanoparticles increases with decreasing average particle size. The k_app value of this photocatalytic degradation of textile dyeing waste water in presence of AuNPs was 0.002/min and β-CD/AuNPs was 0.005/min. This is a non-toxic and eco-friendly approach.

Prospective Application of Nanoparticles Green Synthesized Using Medicinal Plant Extracts as Novel Nanomedicines

The use of medicinal plants in green synthesis of metal nanoparticles is increasing day by day. A simple search for the keywords "green synthesis" and "nanoparticles" yields more than 33,000 articles in Scopus. As of August 10, 2021, more than 4000 articles have been published in 2021 alone. Besides demonstrating the ease and environmental-friendly route of synthesizing nanomaterials, many studies report the superior pharmacological properties of green synthesized nanoparticles compared to those synthesized by other methods. This is probably due to the fact that bioactive molecules are entrapped on the surface of these nanoparticles. On the other hand, recent studies have confirmed the nano-dimension and biocompatibility of metal ash (Bhasma) preparations, which are commonly macerated with biological products and administered for the treatment of various diseases in Indian medicine since ancient times. This perspective article argues for the prospective medical application of green nanoparticles in the light of Bhasma.

Bioinspired Nanomodification Strategies: Moving from Chemical-Based Agrosystems to Sustainable Agriculture

Agrochemicals have supported the development of the agricultural economy and national population over the past century. However, excessive applications of agrochemicals pose threats to the environment and human health. In the last decades, nanoparticles (NPs) have been a hot topic in many fields, especially in agriculture, because of their physicochemical properties. Nevertheless, the prevalent methods for fabricating NPs are uneconomical and involve toxic reagents, hindering their extensive applications in the agricultural sector. In contrast, inspired by biological exemplifications from microbes and plants, their extract and biomass can act as a reducing and capping agent to form NPs without any toxic reagents. NPs synthesized through these bioinspired routes are cost-effective, ecofriendly, and high performing. With the development of nanotechnology, biosynthetic NPs (bioNPs) have been proven to be a substitute strategy for agrochemicals and traditional NPs in heavy-metal remediation of soil, promotion of plant growth, and management of plant disease with less toxicity and higher performance. Therefore, bioinspired synthesis of NPs will be an inevitable trend for sustainable development in agricultural fields. This critical review will demonstrate the bioinspired synthesis of NPs and discuss the influence of bioNPs on agricultural soil, crop growth, and crop diseases compared to chemical NPs or agrochemicals.

A sensitive and smartphone colorimetric assay for the detection of hydrogen peroxide based on antibacterial and antifungal matcha extract silver nanoparticles enriched with polyphenol

Current trends in scientific studies focus on the development of smartphone-based biosensors via green nanoparticle for clinical diagnosis, food, and environmental monitoring. In this study, we developed a novel portable smartphone-based biosensor via green dendrimer-coated matcha extract/silver nanoparticles (ME-Ag NPs) enriched with polyphenol for detecting hydrogen peroxide (H₂O₂). Also, we investigated the biological evaluation of the nanostructure as a safe preservative for use in biomedical applications. Ag NPs were prepared using a green sonochemical method and were characterized to determine surface and chemical properties by different techniques such as scanning electron microscopy-energy-dispersive X-ray, transmission electron microscope, Fourier transform infrared spectroscopy, atomic force microscopy, X-ray diffraction, and Brunauer-Emmett-Teller. Furthermore, antimicrobial and antifungal properties of ME-Ag NPs were investigated against pathogenic microorganisms such as Staphylococcus aureus, Pseudomonas aureginosa, Escherichia coli, Candida albicans, and Aspergillus brasiliensis. The experimental sensor methodology was based on the detection of H₂O₂ by analysis of images of novel silver nanostructure-coated papers and processing of color histograms with a RGB (red-green-blue) analyzer software. Consequently, the smartphone-based biosensor exhibited high sensitivity with detection limits of 0.82 μM response time of 5 s. The smartphone-based biosensor via ME-Ag NPs provided a rapid and selective detection of H₂O₂.

Biosynthesis of silver nanospheres, kinetic profiling and their application in the optical sensing of mercury and chlorite ions in aqueous solutions

Pollution of water linked to microbial decontamination and extensive use of sodium chlorite (NaClO₂) as a disinfectant, especially in the face of the current COVID-19 situation, is a serious water pollution issue that needs to be addressed. In this context, an environmentally friendly and cost-effective method has been developed for the biomimetic synthesis of Ag nanospheres (Ag NSs) using aqueous extract of Piper nigrum for the detection of chlorite (ClO₂^-) and mercury (Hg²⁺) ions. The strong antioxidant properties of the biomolecules present in the Piper nigrum extract reduce silver ions (Ag⁺) to Ag⁰. After optimization of the formulation parameters, it was observed that 1 mL of piper nigrum extract was sufficient to reduce and stabilize 100 mL of 1.5 mM of Ag⁺ in 2.5 h at 30 °C. X-ray diffraction (XRD) pattern of Ag NSs revealed their crystalline nature and the characteristic Bragg's diffraction peaks confirmed their face cubic crystal (FCC) lattice. The characteristic reddish-brown color and absorption surface plasmon resonance (SPR) band at 435 nm confirmed the successful fabrication of Ag NSs. Kinetic analysis revealed a three-phase growth pattern involving nucleation, growth and stabilization. Transmission electron microscopy (TEM) and High-resolution transmission electron microscopy (HRTEM) micrograms, showed spherical NSs with narrow polydispersity with particle size ranging from 10 to 30 nm. The synthesized NSs were exposed to various metal ions and anions. The absorption intensity of Ag NSs quenched in the presence of mercury ions (Hg²⁺) among the cations and Chlorite ions (ClO₂^-) among the anions. The limit of detection (LOD) of 7.47 μM and 1.11 μM was evaluated from the calibration curve for Hg²⁺ and ClO₂^-, respectively. Based on these promising results, it is suggested that the method reported is a low-cost and one step biogenic protocol for the synthesis of Ag NSs and their employment for the detection of Hg²⁺ and ClO₂^-ions.

Green Synthesis of Silver Nanoparticles Using the Flower Extract of Abelmoschus esculentus for Cytotoxicity and Antimicrobial Studies

BACKGROUND

Abelmoschus esculentus (L.) Moench, an economically important malvaceous vegetable crop popularly known as okra, is used in various culinary preparations and is rich in vitamins, minerals, and nutrients. The biological properties of okra flowers in relation to nanoparticle synthesis have not yet been reported.

MATERIALS AND METHODS

In the current study, silver nanoparticles (AgNPs) were synthesized using extracts of the flowers of A. esculentus. The characteristics of the AgNPs were studied using a UV-vis spectrometer, Fourier transmission infrared spectrophotometer (FTIR), X-ray diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive X-ray spectrometer (EDX). Antibacterial activity screening was performed using the agar well diffusion method, and cytotoxicity and cell viability studies were conducted using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

RESULTS

The synthesized AgNPs were spherical and ranged in size from 5.52 to 31.96 nm, with an average size of 16.19 nm, as determined by UV-vis spectroscopy, FTIR, XRD, TEM and EDX. A. esculentus flower extract-mediated silver nanoparticles (AME-AgNPs) exhibited excellent activities in vitro studies, particularly in vitro cytotoxic and antiproliferative studies against cancer cell lines, such as the TERT-4 and A-549 cell lines. The antibacterial effects on the Gram-positive pathogens Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes and the Gram-negative pathogens Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Salmonella typhimurium and Shigella sonnei were tested. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values varied with the bacterial strain. The IC50 values of the synthesized NPs for the tested cell lines were close to that of a standard drug.

CONCLUSION

Compared to other NPs the NPs synthesized in this study were smaller in size and exhibited a higher level of antibacterial activity, cytotoxicity and apoptosis at minimal concentrations, and this is the first study on okra flower-induced anticancer and antimicrobial activities.

Antibacterial Activities of Phytofabricated ZnO and CuO NPs by Mentha pulegium Leaf/Flower Mixture Extract against Antibiotic Resistant Bacteria

Purpose: In this study, leaf/flower aqueous extract of medicinal plant species Mentha pulegium was used to synthesize ZnO and CuO nanoparticles (NPs) as a cost-effective, one-step, and eco-friendly method. Methods: Physicochemical properties of both metal oxide NPs (MONPs) were determined by UV-Vis spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM) and energy dispersive X-ray (EDX) techniques. Results: Phytofabricated ZnONPs and CuNPs illustrated 65.02±7.55 and 26.92±4.7 nm with antibacterial activities against antibiotic-resistant Escherichia coli and Staphylococcus aureus. Higher antibacterial activities were observed for CuONPs compared with ZnONPs. Conclusion: Large surface area and more reactivity resulted from smaller size as well as higher production of reactive oxygen species (ROS) were considered to antibacterial efficiency of CuONPs against antibiotic-resistant E. coli and S. aureus.

Biosynthesis of Novel Silver Nanoparticles Using Eryngium thyrsoideum Boiss Extract and Comparison of their Antidiabetic Activity with Chemical Synthesized Silver Nanoparticles in Diabetic Rats

In the present study, silver nanoparticles (1) were synthesized by green method using Eryngium campestre Boiss aqueous extract and silver nanoparticles (2) were synthesized with chemical method. The silver nanoparticles (1) and (2) were characterized with FT-IR, UV-Vis, XRD, EDX, SEM, and TEM analyses. The effects of silver nanoparticles (1) and (2) were investigated on glucose, hematology, and blood biochemical parameters in alloxan- induced diabetes type 1 model rats. Diabetic or intact rats received intraperitoneal injection of saline or 2.5 mg/kg of silver nanoparticles (1) and (2) for 14 consecutive days. Hematological parameters and serum concentration of FBS, HbA₁C, ALT, AST, GGT, ALP, albumin, creatinine, and urea were determined. Interestingly, silver NPs (1) or (2) did not exert toxic influences on hematological parameters and liver and kidney function in intact rats. Both silver nanoparticles (1) and (2) exert hypoglycemic effects in diabetic rats. They did not alter urea, creatinine, and hematological parameters except white blood cell (WBC) count in diabetic rats. Silver nanoparticles (1) decreased significantly liver enzyme levels including ALT and AST of diabetic rats. However silver nanoparticles (2) could not suppress the increased levels of liver enzymes in diabetic rats. In comparison with silver nanoparticles (2), the silver nanoparticles (1) are more protective than the same dose of silver nanoparticles (2) in the regulation and improving the liver function in diabetic rats. Also, silver nanoparticles (1) may exert protective effects on liver damage of diabetic rats rather than kidney damage.

Synthesis of TiO2 nanoparticles by chemical and green synthesis methods and their multifaceted properties

In this present work, Titanium dioxide nanoparticles (TiO2 NPs) successfully synthesized using the chemical as well as the green synthesis routine. The ethanol provoked the chemical reduction of ions. In the green synthesis, jasmine flower extract was used as a reducing and stabilizing agent because it contains alkaloids, coumarins, flavonoids. The Rutile phase of TiO2 NPs with an average crystalline size of 31–42 nm was revealed from the XRD pattern. From the UV–Visible spectroscopy, the optically active region of TiO2 NPs at 385 nm represents the visible region spectrum. The Ti–O–Ti and Ti–O vibration bond formation confirms the formation of TiO2 NPs. The SEM image of TiO2 NPs reveals that the spherical shaped NPs with randomly arranged manner. The obtained results have revealed that the property of TiO2 nanoparticles was similar in both processes. The Photodegradation of methylene blue dye was investigated and resulted in the maximum degradation efficiency of 92% is achieved at 120 min of irradiation. The Photodegradation study shows the biosynthesized TiO2 NPs exhibits a higher degradation efficiency compared to chemically synthesized TiO2 NPs. The antibacterial activity of prepared TiO2 NP’s was studied using grams-positive and gram-negative strains. The biological activities of green synthesized TiO2 NPs are enhanced compared to the chemically synthesized TiO2 NPs. Hence the degradation efficiency and zone inhibition layer indicate that the prepared TiO2 NPs are the potential candidate for environmental and biomedical applications.

Graphic abstract

Green synthesis of silver nanoparticles using plant extracts and their antimicrobial activities: a review of recent literature

Synthesis of metal nanoparticles using plant extracts is one of the most simple, convenient, economical, and environmentally friendly methods that mitigate the involvement of toxic chemicals. Hence, in recent years, several eco-friendly processes for the rapid synthesis of silver nanoparticles have been reported using aqueous extracts of plant parts such as the leaf, bark, roots, etc. This review summarizes and elaborates the new findings in this research domain of the green synthesis of silver nanoparticles (AgNPs) using different plant extracts and their potential applications as antimicrobial agents covering the literature since 2015. While highlighting the recently used different plants for the synthesis of highly efficient antimicrobial green AgNPs, we aim to provide a systematic in-depth discussion on the possible influence of the phytochemicals and their concentrations in the plants extracts, extraction solvent, and extraction temperature, as well as reaction temperature, pH, reaction time, and concentration of precursor on the size, shape and stability of the produced AgNPs. Exhaustive details of the plausible mechanism of the interaction of AgNPs with the cell wall of microbes, leading to cell death, and high antimicrobial activities have also been elaborated. The shape and size-dependent antimicrobial activities of the biogenic AgNPs and the enhanced antimicrobial activities by synergetic interaction of AgNPs with known commercial antibiotic drugs have also been comprehensively detailed.

Silver Nanomaterials for Wound Dressing Applications

Silver nanoparticles (AgNPs) have recently become very attractive for the scientific community due to their broad spectrum of applications in the biomedical field. The main advantages of AgNPs include a simple method of synthesis, a simple way to change their morphology and high surface area to volume ratio. Much research has been carried out over the years to evaluate their possible effectivity against microbial organisms. The most important factors which influence the effectivity of AgNPs against microorganisms are the method of their preparation and the type of application. When incorporated into fabric wound dressings and other textiles, AgNPs have shown significant antibacterial activity against both Gram-positive and Gram-negative bacteria and inhibited biofilm formation. In this review, the different routes of synthesizing AgNPs with controlled size and geometry including chemical, green, irradiation and thermal synthesis, as well as the different types of application of AgNPs for wound dressings such as membrane immobilization, topical application, preparation of nanofibers and hydrogels, and the mechanism behind their antimicrobial activity, have been discussed elaborately.

Evaluation of the antimicrobial activity of silver nanoparticles obtained by microwave-assisted green synthesis using Handroanthus impetiginosus (Mart. ex DC.) Mattos underbark extract

We describe here a green method for the preparation of silver nanoparticles (AgNPs), by a microwave-assisted synthesis route using Handroanthus impetiginosus underbark extract, with antibacterial activity. After optimizing the synthesis parameters with a Box-Benhken designed experiment, samples were characterized by powder XRD, TEM, UV-Vis spectroscopy, FTIR and zetametry. Using the overall optimized conditions of synthesis - time of reaction 15 min at 200 °C and plant extract/AgNO3 volume ratio equal to 10% - highly crystalline ∼13.4 nm-sized spherical AgNPs in a well-dispersed colloidal state were obtained. It was also proved that the plant extract compounds act as reductant and capping agents during synthesis to functionalize AgNPs, resulting in a negatively charged surface with high values of zeta potential in a wide range of pH, from acidic to alkaline media. Biological activity tests against Staphylococcus aureus and Escherichia coli and cell viability experiments showed that synthesized AgNPs were not toxic to HaCaT mammalian cells and presented a high efficiency against Gram-positive bacteria (S. aureus). This was associated with the synergistic combination of AgNP silver cores with the capping layer containing natural compounds with antimicrobial properties and considered an alternative to the AgNPs commonly obtained from conventional routes that present antibacterial effectiveness preferentially against Gram-negative strains.