Molybdic Acid Research Articles

On the interaction of uric acid with ammonium molybdate in acidic medium

This communication is a theoretical organic chemistry study on the interaction of uric acid with ammonium molybdate in acidic medium (Gigli test for uric acid). Colour tests give rapid, visible, results. However, it is interesting know what is happening in the test tube at molecular level. In the present paper we describe the reaction route of the above mentioned assay. Each step is fully commented and the electron flow is also given. The key stages are: addition of molybdic acid to the C-C double bond, acidolysis of the organometallic ester with reduction to molybdenum (IV) and epoxide formation (oxidation step). Ring opening of the oxirane and reaction with water. A glycol is formed followed by opening of the five-member ring giving a carbonyl and an ureido chain. Finally, elimination of urea gives rise to 2,4,5,6-tetraoxo-hexahydropyrimidine (alloxan) which is hydrated. The blue colour observed (molybdenum blue) is a mixture of several oxides.

Nitrogen Requirement and Nitrogen Form Preference by Radermachera hainanensis and R. sinica Plug Seedlings

Abstract Radermachera hainanensis Merr. and R. sinica Hemsl. are popular foliage plants raised from seeds. Nitrogen fertilizer can significantly influence medium pH and EC, plug seedling growth, and photosynthesis. Plug seedlings of both species, each with one pair of leaves, were subjected weekly to nutrient solutions with nitrogen (N) concentrations ranging from 0 to 32 mM. Nitrogen-deficient plants exhibited the lowest leaf area, SPAD-502 value, and shoot dry weight but the highest root-to-shoot ratio. Leaf area, SPAD-502 value, and root and shoot dry weights increased with increasing N concentration up to 12-16 mM, and gradually decreased thereafter. Well-grown plants with 12-16 mM N exhibited peak maximal fluorescence (Fm), photochemical quenching (qP) and the lowest minimal fluorescence (Fo) and non-photochemical quenching (qN). Seedlings received nutrient solutions with varying proportions of NH4-N: NO3-N (0:100, 25:75, 50:50, 75:25, and 100:0, in percentages) at 16 mM N. Both species exhibited reduced leaf area, SPAD-502 value, and plant dry weights when supplied with only NO3-N or NH4-N. Maximum growth was achieved at a 50% NH4-N: 50% NO3-N ratio. Species used in this study: Golden jasmine tree, Radermachera hainanensis Merr.; China Doll, Radermachera sinica Hemsl. Chemicals used in this study: ammonium nitrate; sodium dihydrogen phosphate; potassium sulphate; potassium nitrate; magnesium sulfate heptahydrate; calcium sulfate dihydrate; calcium nitrate tetrahydrate; ammonium sulfate; boric acid anhydrous; potassium chloride; ferrous sulfate heptahydrate; disodium ethylenediaminetetraacetic acid dihydrate; copper sulfate pentahydrate; zinc sulfate heptahydrate; molybdic acid; manganese sulfate monohydrate; nickel sulfate hexahydrate; sodium hydroxide.

A novel UV-curable composite coating with superior anti-corrosion and mechanical properties

The UV curing method is free from volatile organic compounds (VOC) and exhibits high curing efficiency. However, pore flaws and inadequate mechanical qualities after cure greatly hinder their utilization in metal anti-corrosion. Herein, layered double hydroxides (LDH) supported by molybdic acid and cerium ions were synthesized in situ on the sericite (SC) surface, enhancing the shielding, corrosion inhibition, resin compatibility, and cross-linking density of the coating. Compared with carbon steel immersed in a 3.5 wt% NaCl solution, the incorporation of SC/KH560@LDH reduced the corrosion current density (Icorr) from 2.001 × 10−5 A/cm2 to 7.883 × 10−6 A/cm2. Moreover, the low-frequency impedance of the UV-SC/KH560@LDH coating remained high at 1.939 × 1010 Ω·cm2 after 70 days of immersion in a 3.5 wt% NaCl solution. The excellent corrosion resistance of UV-SC/KH560@LDH can be attributed to the barrier properties of the filler, the chloride ion trapping, and the passivation effect. Furthermore, the UV-curable alkyd resin used in this work formed a chemical bond with the metal substrate, enhancing the mechanical properties of the coating. The adhesion strength of the UV-SC/KH560@LDH was measured at 11.50 MPa. The thickness loss (21.3 μm) of the UV-SC/KH560@LDH were minimal after 5000 cycles of wear. A new research concept for preparing the UV-SC/KH560@LDH with superior anti-corrosion and mechanical properties for carbon steel plate surfaces has been proposed to meet the demands of practical applications.

Effects of Ceria Abrasives on the Chemical Mechanical Polishing of Molybdenum Film with Alkaline H2O2 Slurries

Abstract The impact of ceria abrasives on the chemical mechanical polishing (CMP) of molybdenum (Mo) films was examined in alkaline slurries utilizing H2O2 as an oxidizer and ceria abrasives. The static etching rate (SER) decreased after the addition of ceria abrasives to the alkaline H2O2-based slurry, while the removal rate (RR) increased except for that of the slurry at pH 9. At pH 9, following the etching of the Mo film in an H2O2 solution with ceria, the surface became coated with MoO3 and Ce2Mo4O15 species. These species originated from the interaction between ceria, H2O2, and molybdic acid. The Ce2Mo4O15 particles envelop the MoO3 surface, thereby preventing the etching of loose MoO3 and hindering further oxidation of Mo to MoO3. This process effectively reduces the RR of Mo. Utilizing ceria slurries at appropriate pH values facilitates achieving a smooth surface with a reasonable RR.

Synergistic Enhancement of Supercapacitor Performance: Vanadium‐Substituted Phosphotungstic and Molybdic Acid Combined with Polypyrrole Using Pyridinium and Ammonium Ionic Containing Organic Cation Linkers with Improved Conductivity

High‐performance energy‐storage devices have emerged as a favored choice owing to their remarkable efficiency, sustainability, and environmental friendliness. Nowadays, polyoxometalate (POM)‐based supercapacitor (SC) electrode materials have gained much attention. Herein, a few new POMs and ionic liquid (IL) composites incorporated into conducting polymer as electrode materials for SC applications are reported. The H6[PV3Mo9O40]⋅34H2O (PV3Mo9) and H6[PV3W9O40].34H2O (PV3W9) POMs are treated with tetrabutylammonium chloride and 1‐butyl‐4‐methyl pyridinium chloride (BMP) and finally combined with polypyrrole (PPy) for the SC studies. An extensive array of analytical techniques is employed to delve into the interplay between the constituents within the composite materials, such as Fourier transform infrared spectroscopy, powder X‐ray diffraction, thermogravimetric analysis, nuclear magnetic resonance (1H and 13C), Field‐emission scanning electron microscopy, energy‐dispersive X‐ray stpectroscopy, X‐ray photoelectron spectroscopy, and Brunauer‐Emmett‐Teller surface area. The combined application of these techniques enables us to understand the interaction dynamics within composite materials comprehensively. POM–ILs combination improves the solubility issues of POMs, and doping of PPy enhances the electrochemical performances of the materials. The PV3W9–BMP–PPy symmetric SC cell shows a specific capacitance of 294.79 F g−1 and an energy density of 28.89 Wh kg−1 at 1 A g−1 current density in 0.25 M H2SO4 medium followed by an excellent cycle life of 78.6% after 10,000 galvanostatic charge–discharge cycles. The fabricated SC device is performed to light up the bulbs of red, yellow, and green light emitting diodes for 50, 30, and 28 s, respectively.

Enhancing frictional and corrosion resistance performance in aluminum alloy through in situ growth of NiZnAl-LDH membrane and its modification

Anodized aluminum, due to its inherent porous channels and thin protective layer, exhibits poor corrosion resistance and friction performance in severe environments. In this study, an in-situ growth of a NiZnAl-LDH composite coating was developed on the surface of aluminum. Sodium molybdate and ricinoleic acid were used to modify the coating, enhancing both corrosion resistance and friction performance. Various tests, including SEM, infrared, XPS, XRD, and others, were conducted to analyze the structure, composition, and properties of the synthesized coating. The results confirmed the successful synthesis of NiZnAl-LDH with nitrate intercalation, which were subsequently converted to molybdate intercalation through sodium molybdate modification. Electrochemical tests revealed that the corrosion current decreased by a factor of two compared to a plain LDH coating. Friction experiments demonstrated that the co-modified coating exhibited a minimal friction coefficient of 0.23, outperforming the original LDH coating.

Preparation and Properties of Molybdenum‐modified High‐ortho Thermosetting Phenolic Fiber

AbstractThe study aims to produce thermosetting resin from synthesized molybdenum‐modified high‐ortho thermoplastic phenolic resin through an addition reaction. Then, molybdenum‐modified high‐ortho thermosetting phenolic resin is blended with polyvinyl butyral and undergoes wet spinning to prepare as‐spun fibers and obtain high‐ortho molybdenum phenolic fibers via solution curing, microwave curing, or heat curing. Fourier transform infrared spectroscopy, nuclear magnetic resonance, thermogravimetric analysis, scanning electron microscopy, and fiber strength testing were used to investigate the structure and properties of molybdenum‐modified high‐ortho phenolic fibers. Results showed that adding molybdic acid introduced Mo−O bonds into the molecular chain of high‐ortho phenolic resin, thereby improving the degree of cross‐linking and thermal stability. The residual carbon content of the fibers after heat treatment exceeded 60%, and the elongation at break and the breaking strength of the microwave‐cured fibers reached 4.2% and 155 MPa, respectively, and the mechanical properties were relatively good. The study of high‐ortho phenolic fibers aims to improve their properties and expand their applications through resin modifications. It provides a possible fiber preparation strategy for improving heat‐resistant phenolic fibers, thereby guiding the research of modified high‐ortho phenolic fibers.

FTIR characterization and microbiological application of polyoxometalates molybdic acid and potassium molybdate against MDR bacteria

The discovery of new antibiotics is a major challenge these days, as the emergence of resistant bacterial strains has intensified in recent years and the responsiveness of traditional drugs has been impaired, mainly due to their early use. As a way to overcome this current problem, studies to discover new drugs have intensified and among them are inorganic compounds. The objective of this work was to evaluate the direct antibacterial activity and combined with antibiotics ampicillin, ciprofloxacin and gentamicin of molybdic acid and potassium molybdate. Both compounds were chemically characterized and tested for their ability to inhibit the resistance mechanism presented by the Staphylococcus aureus (K-4100 e K-4414) strain, represented by the expression of the beta-lactamase enzyme. Microbiological tests were carried out using microdilution methodology with colorimetric development, using resazurin. Spectroscopic characterization was performed using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), for molybdic acid, a band located at 952 cm−1 was visualized, while for potassium molybdate the bands detected were located at 319 and 879 cm−1 The compounds did not show direct antibacterial activity, but acted to reinforce the effect of traditional antibiotics: ampicillin, ciprofloxacin and gentamicin, in different situations, against the bacteria Escherichia coli 06 and Staphylococcus aureus 10. Furthermore, the use of molybdates was promising in reversing the resistance mechanism of the bacterial strains Staphylococcus aureus K4100 and K4414. The results obtained are unprecedented for the molybdates tested and imply a better elucidation of the bioactivity of polyoxometalates and present new therapeutic possibilities through the use of molybdates. Toxicological tests and tests with other strains are encouraged through our research to better understand the activity of the compounds used.

Industrial-Scale Technology for Molybdic Acid Production from Waste Petrochemical Catalysts.

The article describes the technology of molybdic acid recovery from spent petrochemical catalysts (HDS) developed and implemented in industrial activity. HDS catalysts contain molybdenum in the form of MoO3 and are used for the hydrodesulfurization of petroleum products. After deactivation, due to the impurities content in the form of sulfur, carbon and heavy metals, they constitute hazardous waste and, at the same time, a valuable source of the Mo element, recognized as a critical raw material. The presented technology allows the recovery of molybdic acid with a yield of min. 81%, and the product contains min. 95% H2MoO4. The technology consisted of oxidizing roasting of the spent catalyst, then leaching molybdenum trioxide with aqueous NaOH to produce water-soluble sodium molybdate (Na2MoO4), and finally precipitation of molybdenum using aqueous HCl, as molybdic acid (H2MoO4). Industrial-scale testing proved that the technology could recover Mo from the catalyst and convert it into marketable molybdic acid. This proves that the technology can be effectively used to preserve molybdenum.

Development of a methodology for phosphorus determination in soils, water, and biofertilizer using digital image analysis - DIA

A new methodology based on Digital Image Analysis (DIA) was developed to determine the phosphorus content in different matrices of soil, aqueous standards, and biofertilizers. P was extracted by the Mehlich-1 method (0.05 mol L−1 HCl + 0.0125 mol L−1 H2SO4), with modifications, where the concentrations of complexing agent ammonium molybdate (AMC), bismuth subcarbonate (SBC) and ascorbic acid mass (AAM) were studied for the formation of the blue phosphomolybdic complex. A 23 factorial design and Dohelert matrix were applied for the study, in addition to the optimization of the variables. A light box was developed to optimize the conditions for obtaining images through smartphones, such as exposure to artificial and natural light and the resolution of smartphone cameras. Images were processed using ImageJ and Chemostat to obtain RGB values. Responses were expressed in terms of the logarithmic function of the ratio between the blank signal and the measured signal Log (R0/R), which showed the best sensitivity with good linear correlation (R2 = 0.9795). The methodology was successfully applied to soil, aqueous standards, and biofertilizer samples. The results did not differ statistically from the values found in the application of the conventional spectrophotometric methodology for α = 0.05. The limits of detection and quantification found in the DIA were, respectively, 1.60 and 2.30 mg dm−3. Addition and recovery tests on aqueous standards, resulted in recoveries between 94 and 102%. The developed methodology is suitable for the determination of P in different matrices such as soil, aqueous standards, and biofertilizers using smartphones.

Mo-modified Pt/CeO2 nanorods with high propane catalytic combustion activity: Comparison of phosphoric, sulphuric and molybdic acid modifications

Catalytic combustion is the most commonly used reaction to purify VOCs. The activation and dissociation of the CH bond over the catalyst becomes a key factor in controlling the rate of the reaction. To identify the factors promoting CH bond decomposition and the roles played by the acidity of the catalyst in propane catalytic combustion, molybdic acid, phosphoric acid, and sulfuric acid were used to acidify CeO2 nanorods, and Pt was then loaded onto the nanorods. The Mo acid modified Pt/CeO2 catalyst purified more than 90% of propane at a high space velocity of 150,000 mL/(g·h) and 300 °C, which is a significant improvement over the Pt/CeO2 catalyst. XRD patterns and TEM images showed that the crystal structure and morphology of CeO2 were not damaged by acid modification. XPS, in situ CO-DRIFTs, NH3-TPD, H2-TPR and other characterization methods were used on Mo acid modified catalysts to explore the reasons for the improved catalytic performance. The results showed that Pt2+ and Pt4+ coexist on 1% Pt/CeO2-18Mo catalyst, and there are more acidic sites, redox sites and adsorbed oxygen. The reaction order test showed the reaction order of molybdic acid modified catalyst to oxygen is -0.4, which is higher than other catalysts, meaning that oxygen is difficult to inhibit the reaction on the catalyst surface. Finally, in situ DRIFTs proved that 1% Pt/CeO2-18Mo catalyst had strong propane adsorption and activation capacity. This catalyst provides new insight into how VOCs can be eliminated more efficiently, green and economically.

IMPACT OF BIO-COMPETITIVE EXCLUSION ON NITRATE-REDUCING BACTERIA IN OIL RESERVOIR WATER TREATMENT

<p>In the presence of nitrogen oxides, nitrate-reducing bacteria (NRB) may use nitrate as an electron acceptor, reduce nitrate to nitrite, and finally convert nitrite to nitrogen or ammonium (NO and N2O). Studies have shown that BCX (Bio-Competitive Exclusion) is a viable , ecologically benign, and low-cost technique for regulating NRB in its first phases of study and application. More precisely, Pseudomonas sp. to isolate nitrate-reducing bacteria from oil-field wastewater using 16S rDNA sequencing and selection (NRB). Including NO3 and NO2 as bio-activators has helped researchers get a deeper understanding of the processes that govern NRB activation. The potential for molybdate and NRB to inhibit Sulfate-Reducing Bacteria (SRB) was also investigated. The results showed that NO2 was more effective than NO3. The effect was greatest at a 1:4 ratio of NO3 to NO2. NRB activation synergized with low molybdic acid solution concentrations (5%). Static corrosion model experiments demonstrated the importance of SRB in the corroding process. Biological inhibitors were shown to have the lowest corrosion rates, proving their effectiveness. Scanning electron microscopy was used to examine the corroded steel sheet's surface morphology. In addition, there was almost no surface corrosion or pitting on the steel sheet.</p>

Extraction and Recovery of Metals from Spent HDS Catalysts: Lab- and Pilot-Scale Results of the Overall Process

The present study proposes an overall recycling process for spent hydrodesulfurization (HDS) catalysts. The process put together stages already known in the technical literature, tested again with samples coming from the roasting stage in a pilot kiln, which is the most limiting stage of metal recovery from spent catalysts. These catalysts contain valuable metals like cobalt (Co), molybdenum (Mo), nickel (Ni), and vanadium (V). In particular, one Co-Mo catalyst was treated in order to optimize the roasting step (time, soda ash, and temperature) at a pilot scale and thus maximize the extraction yield of molybdenum (Mo) and vanadium (V). In particular, a dry Co-Mo catalyst was used. After roasting at 700 °C for 2.5 h, the best conditions, the catalysts underwent water leaching, separating Mo and V from Co and the alumina carrier, which remained in the solid residue. The pregnant solution was treated to remove arsenic (As) and phosphorus (P), representing the main impurities for producing steel alloys. V was precipitated as NH4Cl, and further calcined to obtain commercial-grade V2O5, whereas Mo was recovered as molybdic acid by further precipitation at a pH of around one. Thus, molybdic acid was calcined and converted into commercial-grade MoO3 by calcination. The hydrometallurgical section was tested on a lab scale. The total recovery yield was nearly 61% for Mo and 68% for V, respectively, compared with their initial concentration in the spent Co-Mo catalysts.

Molybdenum Blues with Tunable Light Absorption Synthesized by Femtosecond Laser Irradiation of Molybdenum Trioxide in Water/Ethanol Mixtures

AbstractMolybdenum blues (MBs) have attracted increasing attention due to their tunable structures and properties, which make them applicable in numerous fields. In this work, a novel strategy to synthesize MB nanorings by irradiating MoO3 suspended in water/ethanol mixtures with intense femtosecond laser pulses is demonstrated. It is found that the MoO3 can be dissolved in the water during laser irradiation to form molybdic acid, which provides an acidic environment for the formation of MB. Concentrations of ethanol as low as 1% result in the formation of MB and by adjusting the concentration of ethanol in the solvent, the absorption band can be tuned due to the modification of MoVOMoVI entities. The MB synthesized in 30% ethanol appears the darkest blue and assembly of vesicles 115 nm in size is observed. At high concentrations of ethanol (>70%), HXMoO3 and MoO3‐X are preferentially formed instead of MB. The photothermal conversion efficiency of the MBs synthesized in 1% and 30% ethanol is above 40%.

Thermal kinetics study on the conversion of β-MoO3 to α-MoO3; A molybdenite concentrate derivative as a catalyst

Herein, thermal decomposition kinetics of molybdic acid (MA) obtained from the leaching of molybdenite concentrate are extensively studied as a precursor for the preparation of molybdenum trioxide (MoO3). The thermal kinetics equation of the reaction suggests that the precursor (MA, H2MoO4.H2O) is converted to β-MoO3 and then to α-MoO3 due to the heating process, giving rise to a transformation temperature of 260-320°C, the average activation energy of about 26.53 ± 0.02 kJ/mol, and a pre-exponential factor of 107 1/min for the transformation of β-MoO3 to α-MoO3. Moreover, differential scanning calorimetry reveals that the volume diffusion mechanism controls the crystallization reaction, leading to the decomposition of MA. Our results indicate that Johnson-Mehl-Avrami (JMA) kinetics with nucleation and three-dimensional growth mechanism can model the experimental data with acceptable accuracy. The catalytic attributes of the stable β-MoO3/α-MoO3 compound provided an efficiency of over 89 % for the oxidation process of methanol to formaldehyde.

The effect of inhibiting molybdate used in anodizing-conversion treatment to improve corrosion protection of AA2030 aluminum alloy in different steps

In this article, different treatment baths for corrosion protection of 2030 aluminum alloy in addition to replacing the hexavalent chromium due to the European recommendation were employed. This work is divided into three steps of treatment: first, anodization using molybdate inhibitor without and with phosphoric acid and, then, pre-oxidation with sodium hydroxide. In the last step, we studied the influence of conversion coating with the combination of sodium molybdate and fluoride on the anodic layer formed on aluminum alloy 2030. In order to characterize the formed layers, we use microstructural characterization (SEM, AFM, and nano-indentation), which allows highlighting the surface condition as well as the morphological distribution, and electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy which shows that the anodization treatment of the aluminum alloy with phosphoric acid and sodium molybdate offered better corrosion resistance. This resistance increased with the use of pre-oxidation and then reached a maximum value of 99.8% efficiency with the addition of the molybdate conversion coating which causes an increase in the double layer and gave an alternative possibility of chromium VI.

Influence of the Pore Structure of Molybdic Acid Immobilized Silica-alumina Hollow Spheres on Acid-promoted Hydrogen Evolution from Ammonia Borane

Influence of the Pore Structure of Molybdic Acid Immobilized Silica-alumina Hollow Spheres on Acid-promoted Hydrogen Evolution from Ammonia Borane

Optimalisation of the Activation Medium and Effect of Inhibiting Activities of Acid Phosphatase, Lactate Dehydrogenase and β-N-Acetylglucosaminidase on the Fertilisation Success of Eurasian Perch (Perca fluviatilis L.).

Simple SummaryThe purpose of this study is to determine the composition of the optimal activating solution for activating sperm motility and perch eggs, because scientific studies and reproductive procedures should be conducted in stable and repeatable conditions. We found that the best activating solution was composed of 80 mM NaCl, 20 mM KCl, 10 mM Tris, with pH 8.0 and 206 mOsm/kg. In spite of this, we also checked the influence of adding the enzyme inhibitors, such as ammonium molybdate–acid phosphatase inhibitor, gossypol – lactate dehydrogenase inhibitor and acetamide–β-N-acetylglucosaminidase inhibitor on perch sperm motility and successful perch fertilisation. We showed that the addition of acid phosphatase inhibitor in perch semen did not affect the process of fertilisation; in contrast, the addition of lactate dehydrogenase and β-N-acetylglucosaminidase inhibitors significantly decreased the percentage of perch fertilised eggs.Although methods for the artificial reproduction of perch have been developed, a lack of information remains regarding the enzymes present in its semen, as well as their role in the fertilisation process. In this study, we first select the optimal activating solution for perch fertilisation and then determine the inhibition effect of enzymes that have already been reported as present in the sperm of teleosts—acid phosphatase (AcP), lactic dehydrogenase (LDH) and β-N-acetylglucosaminidase (β-NAGase)—on the percentage of motile spermatozoa and fertilised eggs. Of the 8 studied activation media, a solution composed of 80 mM NaCl, 20 mM KCl, 10 mM Tris, with pH 8.0 and 206 mOsm/kg proved to be optimal for perch gametes. The addition of ammonium molybdate (AcP inhibitor) caused no significant reduction in the percentage of fertilised eggs. On the other hand, the addition of 0.25 mM gossypol (LDH inhibitor) and 0.125 M acetamide (β-N-acetylglucosaminidase inhibitor) significantly decreased the fertilisation percentage to 41.1% and 52.4%, respectively, in contrast to the control (89.9 %). Both LDH and β-NAGase thus seem to play a very important role in the perch fertilisation process.

Silica-Supported Molybdic Acid-Catalyzed Synthesis of New and Known Chromeno-Pyrano[2,3-b]Quinolines through a Green Route

A capable manner for the preparation of chromeno-pyrano[2,3-b]quinoline compounds is outlined. Pyrano[3,2-c]chromene-3-carbonitriles are synthesized via the one pot three-component reaction of aryl aldehydes, malononitrile and 4-hydroxycoumarin in the presence of silica sodium carbonate (SSC) as a heterogeneous basic catalyst. Next, the prepared pyrano[3,2-c]chromene-3-carbonitrile is reacted with cyclohexanone by using silica-supported molybdic acid (SSMA) as a worthy and recyclable catalyst for producing recognized and unrecognized chromeno-pyrano[2,3-b]quinoline derivatives under solvent-free conditions in good to excellent yields.

Green Synthesis of Silver Nanoparticles Incorporated Aromatherapies Utilized for Their Antioxidant and Antimicrobial Activities against Some Clinical Bacterial Isolates

There is a need to synthesize eco-friendly nanoparticles with more effective and potent antibacterial activities. A green and cost-effective method for the synthesis of silver nanoparticles (AgNPs) using Thymus vulgaris, Mentha piperita, and Zingiber officinale extracts was developed. The analytical instrumentation, namely, UV/Vis, absorption spectroscopy, FTIR, and scanning electron microscopy (SEM), was used to determine the developed AgNPs, confirming the functional groups involved in their reduction. Acidic molybdate, DPPH, and FRAP regents were reacted with AgNPs extract to evaluate their antioxidant, scavenging, and oxidative activities. The agar well diffusion method was used to determine the antibacterial potential of AgNPs extracts using clinical isolates. The developed AgNPs showed peaks at 25 cum\\Diff, 50 cum\\Diff, and 75 cum\\Diff, respectively, of 16.59 ± 0.78, 45.94 ± 1.07, and 81.04 ± 0.98 nm, for Thymus vulgaris, Mentha piperita, and Zingiber officinale. SEM revealed uniform prepared and encapsulated AgNPs by plant extracts matrix. The FTIR shows the involvement of amide (-CO-NH2), carbonyl (-CO), and hydroxyl (-OH), which resulted in the reduction of AgNPs. The AgNPs extract showed significantly higher TAA, DPPH, and FRAP values than free AgNPs and plant extract (p < 0.05). Antibacterial of AgNPs extracts revealed various degrees of inhibition zones against Escherichia coli, Acinetobacter baumannii, and Staphylococcus aureus. The developed AgNPs extract showed acceptable antioxidant activities and noticeable antibacterial potential. The prepared green synthesized AgNPs showed a promising antibacterial activity against four multidrug-resistant clinical isolates, Escherichia coli, Acinetobacter baumannii, and Staphylococcus aureus. Further, fractionated extracts other than crude extracts will be utilized in the preparation of AgNPs to get more efficient antibacterial activities for future work.