Startseite Biosynthesis, characterization and anti-microbial activity of silver nanoparticle based gel hand wash
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Biosynthesis, characterization and anti-microbial activity of silver nanoparticle based gel hand wash

  • Mohammed Muqtader Ahmed EMAIL logo , Farhat Fatima , Md. Khalid Anwer EMAIL logo , Saad M. Alshahrani , Ahmed Alalaiwe und Prakash Katakam
Veröffentlicht/Copyright: 27. Mai 2019
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Green Processing and Synthesis
Aus der Zeitschrift Green Processing and Synthesis Band 8 Heft 1

Abstract

In the current study, silver nanoparticles (AgNPs) were biosynthesised by microwave irradiation using Azadirachta indica. The formation of AgNPs was confirmed by surface plasmon resonance (SPR) band at 408 nm at UV-visible spectroscopy due to reduction of silver metal into (AgNPs) and further confirmed its particles in nano range. Nine different smart-gel hand wash were prepared by dispersing (AgNPs) in the HPMC and/or Pluronic F-127 polymers. The prepared smart gel hand wash was optimized based on pH, viscosity, spreadability, foamability, clarity. The optimized hand wash (NH5) had pH (6.6 ± 0.33), viscosity (66 ± 0.77, cp), spreadability (24.34 g-cm/s), foamability (100 mL). The optimized hand wash (NH5) showed a superior efficacy against pathogenic organisms in comparison to germ protection based marketed hand wash.

Keywords: silver nanoparticles; smart-gel hand wash; anti-microbial efficacy; stability

1 Introduction

Hand washing is a religious and cultural habit, the relation between handwashing and infectious disease was recognized only two centuries ago by a Hungarian doctor Ignaz Semmelweis, known as the father of hand hygiene [1,2]. He noticed the spread of infection and mortality of new born given birth in his hospital, which was relatively higher than the adjacent midwife-run maternity hospital. In his investigation, he concluded that doctors with bare hands after performing surgery or autopsy visited the maternity ward were the cause to transmit the infection in new-borns and causes death [3]. In the present scenario challenges of the 21st century include infectious diseases; the second leading cause of death that kills 17 million people in a year worldwide [4]. Majorly transmission of infection takes place by contaminated hands, therefore hand plays a vital role in the spread of infectious diseases in the healthcare setups, industrial setting related to the food manufacturing and also in the community to larger extent [5,6]. Hand hygiene as an intervention to prevent the spread of infections, the term hygiene was derived from the Greek healing goddess Hygeia. In 1961 the Centre for disease control and prevention (CDC) recommended hand wash for health care workers. The recent guideline recommends, use of waterless antiseptic agents instead of soap and water for hand wash [7,8]. Hand hygiene preparation with soap may damage the skin and increases microbial growth over the time. Usage of soap in hand wash may damage the skin which could be more prone to microbial colonization [9,10].

Reports on Triclosan an active antiseptic ingredient commonly used in hand wash proved ineffective than using plain soap [11]. Nowadays researchers pay more attention in natural medicine due to its safety and dependability as compared with synthetic medicine that causes deleterious effects. Nature is the reliance of remedies for all ailments of mankind. Until now, 1340 plants and over 30,000 antimicrobial constituents have been isolated from plant sources [12,13]. Azadirachta indica (Neem) leaf showed antimicrobial and antifungal activity due to quercetin, beta-sitosterol, polyphenolic flavonoids [14]. Azadirachta indica is an evergreen plant native of India and found in most tropical countries belongs to the family Meliaceae [15]. Metallic nanoparticles are emerging as novel class of biomedical material applied for hygiene in daily to day life. Silver nanoparticles (AgNPs) were the clusters of silver (Ag) atoms ranged from 1-100 nm showed predominant robust cytotoxicity to different bacterial cells by interacting with functional group on the bacterial cell membrane and inactivate bacteria. Silver in the presence of water converts to level 1 (Ag+) which could be reactive and binds to protein of the bacteria act as bactericidal [16, 17, 18, 19].

Thus the present study aims to biosynthesis AgNPs by microwave irradiation using silver nitrate and neem leaf extract solution. The AgNPs synthesis was confirmed by surface plasmon resonance (SPR) band and formed AgNPs was incorporated in smart-gel hand wash by using different polymers.

2 Materials and methods

2.1 Materials

Silver nitrate, Hydroxypropyl Methyl Cellulose (HPMC), Pluronic-F-127, Sodium lauryl sulphate were purchased from Sigma-Aldrich, USA. Fresh neem leaves of Azadirachta indica were collected from the local area. Glycerine and trietanolamine obtained from SD Fine Chemical Ltd. Agar was purchased from Hi-Media laboratories, other chemical were used of analytical grades.

2.2 Microwave irradiation assisted green synthesis of silver nanoparticles

Locally available Azadirachta indica leaves, authenticated by botanist were selected and rinsed thoroughly many a times with tap water followed by ion free water. 5 g of young leaves was subjected for size reduction in ball mill by adding 100 mL of distilled water then aqueous extract was filtered through Whatman No. 1 filter paper. 5 mL filtrate as reducing agent was added in 100 mL of 1 mM of silver nitrate. Then the solution was taken in a closed round bottom flask and mounted on a ring placed in microwave oven “(Samsung Model ME0113M1)” operated at power output 900 W, irradiated by microwave heat until the solution turned to colloidal dispersion of yellowish brown colour indicates the formation of silver nanoparticles. The formation of AgNPs was confirmed by UV-Visible absorption Surface Plasmon Resonance (SPR) spectrum [20,21].

2.3 Formulation of smart hand wash entrapped with bio silver nanoparticles

The microwave irradiation assisted biosynthesised AgNPs, subjected to ultracentrifugation at 10000 rpm for 4 h. The sediment was collected and dried at room temperature, and utilized for the preparation of smart hand wash, nine sets of gel hand wash (NH1-NH9) were prepared as per the composition mentioned in the Table 1. The smart-gel hand wash were prepared by dispersing in hydrophilic thermoresponsive polymer (Pluronic F-127) in the sufficient amount of purified water with continuous stirring at 1000 rpm, then add sodium lauryl sulphate (SLS) 1% and 2% glycerine. Desired quantity of trietanolamine then added to adjust pH. Finally fragrance was added and final volume is made up with distilled water up to 100 mL and mixed at 300 rpm under ultrasonication for 10 min [22,23].

Table 1

Smart hand wash formulation compositions.

FormulationAgNPsHPMCPluronic(F127)SLSGlycerineFragrance
code*(mg)(% w/v)(% w/v)(% w/v)(% w/v)(% w/v)
NH11.51–120.5
NH21.51.5–120.5
NH31.52–120.5
NH41.5–1120.5
NH51.5–1.5120.5
NH61.5–2120.5
NH71.511120.5
NH81.511.5120.5
NH91.512120.5

  1. *Each formula consists of distilled water up to 100 mL. All formulations were neutralized by triethanolamine to pH=6.8

2.4 Characterizations of bio AgNPs entrapped in smart hand wash

2.4.1 UV-Visible measurements

Spectral analysis of the fabricated nanoparticles was carried out using JASCO 730- UV–Vis spectrophotometer.

The spectra were scanned in the range of 300 to 700 nm wavelength with resolution of 1 nm at room temperature. The surface Plasmon resonance band (SPR) at visible range of wavelength was monitored to confirm AgNPs formation.

2.4.2 Particle size measurement

Biosynthesized AgNPs were suspended in distilled Milli Q treated water (pH 7) and characterized for particle size by Nanotrac particle size analyzer (Microtrac, S3500) [24]. The colloidal solution of AgNPs was analysed at 25°C with an angle of detection of 90°. Each measurement was done in triplicate.

2.4.3 pH measurement

Formulated smart hand wash were evaluated for pH to check the skin compatibility by using a pH meter (SensoDirect, Lovibond- Germany) the results were tabulated in Table 2.

Table 2

Characteristic parameters of smart-gel hand wash entrapped with AgNPs.

FormulationpHViscositySpreadabilityFoamability
Code(cp)g-cm/s(mL)
NH16.4 ± 0.13150 ± 0.2322.1395
NH26.6 ± 0.17280 ± 0.4520.6595
NH36.3 ± 0.21445 ± 0.4119.6790
NH46.8 ± 0.1440 ± 0.3326.87100
NH56.6 ± 0.3366 ± 0.7724.34100
NH66.4 ± 0.7489 ± 0.6322.3290
NH76.5 ± 0.84310 ± 0.2321.9895
NH86.6 ± 0.11420 ± 0.1620.0385
NH96.4 ± 0.12880 ± 0.2318.5485

2.4.4 Viscosity measurement

The flowability of the prepared formulation was determined by Brookfield DV-I Prime viscometer (Brookfield, Massachusetts, USA). The sample adapter (spindle), rotated at an optimum speed, the sample is placed in flow jacket to maintain a constant room temperature and allowed to settle for 5 min prior to taking the reading. The rheological results showed in Table 2.

2.4.5 Spreadability measurement

Multimer [25] method used to determine the spreadability by placing the smart-gel hand wash under investigation in between two glass plates of 05x20 cm. 500 g weight was placed for 5 min to disperse the content, the weight was removed and the 50 g of weight was then attached to the pulley connected to the upper layer. The bottom glass plate was fixed to a wooden table. The upper glass plate rolls over the bottom plate the time required to travel for 10 cm was noted and spreadability was measured by the below formulae and presented in g-cm/s. The spreadability was determined by special fabricated apparatus and it was calculated using the formula (Eq. 1):

(1)S=mlt

where:

S – spreadability

m – weight tied to the upper slide

l – length of the glass slide

t – time taken in seconds.

2.4.6 Foamability measurement

Smart-gel hand wash (5 g) was taken in 100 mL measuring cylinder, agitated for 10 times in 50 mL of tap water, and final volume was measured in mL, the results were given in Table 2.

2.4.7 Clarity measurement

The smart-gel hand wash was evaluated for clarity by placing the three different concentrations (10% w/v, 25% w/v and 50% w/v) of content in a 1 cm quartz cuvette and scanned at 400 nm using UV-Visible spectrophotometer. The % transmission was of the sample noted to measure the clarity of the product.

2.4.8 In vitro anti-microbial activity

The antimicrobial activity of the smart-gel hand wash (NH5) was aseptically evaluated by dip well agar diffusion technique against Staphylococcus aureus and Candida albicans [26]. A well was excavated (0.85 cm) in the plates containing 15 mL of Muller-Hilton agar medium. 100 μL (15 mg/L) aqueous suspension of AgNPs entrapped in smart-gel hand wash and germ protection based marketed hand wash was introduced in the different wells of petri plates. The dip wall filled with normal saline served as the control. The plates were incubated overnight at 37°C in the incubator. The efficacy of the developed smart-gel hand wash was determined by measuring the zone of inhibition in diameter (mm).

2.4.9 Stability study

The stability studies was performed as per the ICH guidelines [27] by keeping the product in screw tight vial in a humidity chamber at RH 75 ± 5% and temperature 40 ± 2°C for a period of 1 month and examined for change in colour and pH.

3 Results and discussion

3.1 Fabrication mechanism of bio silver nanoparticles

The hypothetical mechanism involved in the fabrication of bio silver nanoparticles was the presence of reducing enzymes in neem aqueous extract filtrate that reacts with silver ion of AgNO3, henceforth used as scaffolds in the fabrication of Silver nanoparticles, further terpenoids present in azadirachta indica extract acts as a surfactants to stabilized the synthesized AgNPs.

3.2 Characterizations of bio AgNPs entrapped in smart hand wash

3.2.1 UV-Visible measurements

The formation of microwave irradiated green AgNPs in the aqueous neem extract was observed due to colour change to yellowish brown which was confirmed by UV-Visible spectrum (Figure 1). A sharp and intense SPR band observed around wavelength 408 nm due to transverse and longitudinal plasmon vibration and difference in dielectric properties between SPR and inters band transition in Ag [28].

Figure 1 UV-Visible spectrum of biosynthesised silver nanoparticles.
Figure 1

UV-Visible spectrum of biosynthesised silver nanoparticles.

3.2.2 Particle size measurement

The mean particle size of synthesized AgNPs was measured as 50.47 nm with a very low polydispersity index 0.326. Narrow dispersion of particles recognized as monodisperse as could be seen in Figure 2.

Figure 2 Particle size distribution of biosynthesised silver nanoparticles.
Figure 2

Particle size distribution of biosynthesised silver nanoparticles.

3.2.3 pH measurement

The pH of all smart-gel hand wash (NH1-NH9) were found to be in the range of 6.3 ± 0.21 to 6.8 ± 0.14 which is considered to be compatible with the skin to avoid the irritation during hand wash.

3.2.4 Viscosity measurement

The rheological study of smart-gel hand wash (NH1-NH9) indicated that the viscosity of HPMC based hand wash increased by increasing the concentration of the polymer the same pattern was observed for Pluronic F-127 polymer. The viscosity of NH7-NH9 was relatively high as compared with another set of smart-gel hand wash. The smart-gel hand wash (NH4-NH6) containing thermo responsive polymer (Pluronic F127)

showed increased in viscosity during hand wash due to physiological temperature 37°C, that can enhance the antimicrobial efficacy of synthesized of AgNPs by prolonged contact time.

3.2.5 Spreadability measurement

The results of spreadability of prepared smart-gel hand wash (NH1-NH9) were tabulated in Table 2. The spreadability of was smart-gel hand wash was found in the range of 18.54 to 26.87 g-cm/s. The results were in the agreement of viscosity, as the viscosity increased the spreadability was found to be decrease and the product with least viscosity value is said to spread more on the palm during application of smart-gel hand wash.

3.2.6 Foamability measurement

The results of foamability prepared smart-gel hand wash (NH1-NH9) were documented in Table 2. The maximum production of foam were observed for pluronic 127 based smart-gel hand wash and least foam was generated by NH8 & NH9 smart-gel hand wash composed of both HPMC and Pluronic F-127 polymers. It was also observed that less amount of water consumed if the formulation has maximum foamability. Formation of foam was due to 1% SLS surfactant added into the smart-gel hand wash. Foam or lather of surfactants act by reducing the surface tension between the water and oil or sebum on the hand and washed away the dirt or other visible stains.

3.2.7 Clarity measurement

The prepared smart-gel hand wash (NH1-NH9) were assessed for its clarity by measuring % Transmittance as compared to transparent clear products and the results revealed that the smart-gel hand wash (NH4) has highest transmittance and clear solution due to the lowest concentration of Pluronic polymer. However, smart-gel hand wash (NH9) showed the lowest clarity due to the high concentration and combination of HPMC and Pluronic polymer in the ratio of 1:2 respectively. Clarity % transmittance decreased with increased in the solution concentration and polymer ratio due to turbidity formed by micelle formation (Figure 3). From the above physical characterization smart-gel hand wash (NH5) was found to be relatively excellent in all parameters hence considered to be promising for further exploitation in antimicrobial studies.

Figure 3 Clarity measurement by % transmittance in three different concentrations.
Figure 3

Clarity measurement by % transmittance in three different concentrations.

3.2.8 In vitro anti-microbial activity

The antimicrobial activity of the smart hand wash was tested against bacterial Staphylococcus aureus and fungal pathogenic organisms Candida albicans. The three dip well in each microorganism petri plate were filled with 100 μL (15 mg/L) of NaCl (F0), optimized smart hand wash (NH5) and MH germ protection based marketed hand wash (Figure 4). The order of zone of inhibition was found to be significantly higher for the developed smart-gel hand wash (NH5) as compared to control (NaCl) and marketed germ protection detergent based marketed product (Table 3). The antibacterial activity of optimized smart-gel hand wash (NH5) probably due to the change in membrane permeability and degradation of bacterial enzymes [29].

Figure 4 In vitro anti-microbial activity of different smart-gel hand wash (NH1-NH9).
Figure 4

In vitro anti-microbial activity of different smart-gel hand wash (NH1-NH9).

Table 3

In vitro anti-microbial activity.

MicroorganismsZone of inhibition (mm)
F0NH5MH
Staphylococcus aureus5 ± 1.250 ± 4.58 ± 1.9
Candida albicans7 ± 1.438 ± 2.46 ± 1.2

3.2.9 Stability study

The results of colour and pH before and after stability testing were assessed, no significant changes were observed after 1 month of study.

4 Conclusion

In the present study, it can be concluded that the formulation NH5 which is composed of thermoresponsive Pluronic F-127 polymers has shown the excellent pharmaceutical performance and antimicrobial activity, in addition, during hand wash consistency of smart-gel hand wash may be increased that in turns increases the antimicrobial activity, henceforth smart-gel hand wash (NH5) considered to be the best smart-gel hand wash. Hence, it was concluded that the developed smart-gel hand wash benefits from its nano size and found biocompatible, efficacious and cost-effective for sanitizing the hand for day to day activities. AgNPs loaded hand wash in gel form can therefore be good replacement for the conventional hand wash.

Tel.: 00966-0506735642, Office: 0115886076

Acknowledgement

The Deanship of Scientific Research, Prince sattam Bin Abdulaziz University, Alkharj, Saudi Arabia funded this project (Project no. 2017/03/7329 H).

  1. Conflict of interest: No conflict of interest is associated with this study.

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Received: 2018-11-08
Accepted: 2019-03-26
Published Online: 2019-05-27
Published in Print: 2019-01-28

© 2019 Ahmed et al., published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 Public License.

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  58. Optimization of the asymmetric synthesis of (S)-1-phenylethanol using Ispir bean as whole-cell biocatalyst
  59. Synthesis of pyrazolopyridine and pyrazoloquinoline derivatives by one-pot, three-component reactions of arylglyoxals, 3-methyl-1-aryl-1H-pyrazol-5-amines and cyclic 1,3-dicarbonyl compounds in the presence of tetrapropylammonium bromide
  60. Preconcentration of morphine in urine sample using a green and solvent-free microextraction method
  61. Extraction of glycyrrhizic acid by aqueous two-phase system formed by PEG and two environmentally friendly organic acid salts - sodium citrate and sodium tartrate
  62. Green synthesis of copper oxide nanoparticles using Juglans regia leaf extract and assessment of their physico-chemical and biological properties
  63. Deep eutectic solvents (DESs) as powerful and recyclable catalysts and solvents for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones
  64. Biosynthesis, characterization and anti-microbial activity of silver nanoparticle based gel hand wash
  65. Efficient and selective microwave-assisted O-methylation of phenolic compounds using tetramethylammonium hydroxide (TMAH)
  66. Anticoagulant, thrombolytic and antibacterial activities of Euphorbia acruensis latex-mediated bioengineered silver nanoparticles
  67. Volcanic ash as reusable catalyst in the green synthesis of 3H-1,5-benzodiazepines
  68. Green synthesis, anionic polymerization of 1,4-bis(methacryloyl)piperazine using Algerian clay as catalyst
  69. Selenium supplementation during fermentation with sugar beet molasses and Saccharomyces cerevisiae to increase bioethanol production
  70. Biosynthetic potential assessment of four food pathogenic bacteria in hydrothermally silver nanoparticles fabrication
  71. Investigating the effectiveness of classical and eco-friendly approaches for synthesis of dialdehydes from organic dihalides
  72. Pyrolysis of palm oil using zeolite catalyst and characterization of the boil-oil
  73. Azadirachta indica leaves extract assisted green synthesis of Ag-TiO2 for degradation of Methylene blue and Rhodamine B dyes in aqueous medium
  74. Synthesis of vitamin E succinate catalyzed by nano-SiO2 immobilized DMAP derivative in mixed solvent system
  75. Extraction of phytosterols from melon (Cucumis melo) seeds by supercritical CO2 as a clean technology
  76. Production of uronic acids by hydrothermolysis of pectin as a model substance for plant biomass waste
  77. Biofabrication of highly pure copper oxide nanoparticles using wheat seed extract and their catalytic activity: A mechanistic approach
  78. Intelligent modeling and optimization of emulsion aggregation method for producing green printing ink
  79. Improved removal of methylene blue on modified hierarchical zeolite Y: Achieved by a “destructive-constructive” method
  80. Two different facile and efficient approaches for the synthesis of various N-arylacetamides via N-acetylation of arylamines and straightforward one-pot reductive acetylation of nitroarenes promoted by recyclable CuFe2O4 nanoparticles in water
  81. Optimization of acid catalyzed esterification and mixed metal oxide catalyzed transesterification for biodiesel production from Moringa oleifera oil
  82. Kinetics and the fluidity of the stearic acid esters with different carbon backbones
  83. Aiming for a standardized protocol for preparing a process green synthesis report and for ranking multiple synthesis plans to a common target product
  84. Microstructure and luminescence of VO2 (B) nanoparticle synthesis by hydrothermal method
  85. Optimization of uranium removal from uranium plant wastewater by response surface methodology (RSM)
  86. Microwave drying of nickel-containing residue: dielectric properties, kinetics, and energy aspects
  87. Simple and convenient two step synthesis of 5-bromo-2,3-dimethoxy-6-methyl-1,4-benzoquinone
  88. Biodiesel production from waste cooking oil
  89. The effect of activation temperature on structure and properties of blue coke-based activated carbon by CO2 activation
  90. Optimization of reaction parameters for the green synthesis of zero valent iron nanoparticles using pine tree needles
  91. Microwave-assisted protocol for squalene isolation and conversion from oil-deodoriser distillates
  92. Denitrification performance of rare earth tailings-based catalysts
  93. Facile synthesis of silver nanoparticles using Averrhoa bilimbi L and Plum extracts and investigation on the synergistic bioactivity using in vitro models
  94. Green production of AgNPs and their phytostimulatory impact
  95. Photocatalytic activity of Ag/Ni bi-metallic nanoparticles on textile dye removal
  96. Topical Issue: Green Process Engineering / Guest Editors: Martine Poux, Patrick Cognet
  97. Modelling and optimisation of oxidative desulphurisation of tyre-derived oil via central composite design approach
  98. CO2 sequestration by carbonation of olivine: a new process for optimal separation of the solids produced
  99. Organic carbonates synthesis improved by pervaporation for CO2 utilisation
  100. Production of starch nanoparticles through solvent-antisolvent precipitation in a spinning disc reactor
  101. A kinetic study of Zn halide/TBAB-catalysed fixation of CO2 with styrene oxide in propylene carbonate
  102. Topical on Green Process Engineering
https://doi.org/10.1515/gps-2019-0027
Schlagwörter für diesen Artikel
silver nanoparticles; smart-gel hand wash; anti-microbial efficacy; stability
Creative Commons
BY 4.0

Artikel in diesem Heft

  1. Regular Articles
  2. Studies on the preparation and properties of biodegradable polyester from soybean oil
  3. Flow-mode biodiesel production from palm oil using a pressurized microwave reactor
  4. Reduction of free fatty acids in waste oil for biodiesel production by glycerolysis: investigation and optimization of process parameters
  5. Saccharin: a cheap and mild acidic agent for the synthesis of azo dyes via telescoped dediazotization
  6. Optimization of lipase-catalyzed synthesis of polyethylene glycol stearate in a solvent-free system
  7. Green synthesis of iron oxide nanoparticles using Platanus orientalis leaf extract for antifungal activity
  8. Ultrasound assisted chemical activation of peanut husk for copper removal
  9. Room temperature silanization of Fe3O4 for the preparation of phenyl functionalized magnetic adsorbent for dispersive solid phase extraction for the extraction of phthalates in water
  10. Evaluation of the saponin green extraction from Ziziphus spina-christi leaves using hydrothermal, microwave and Bain-Marie water bath heating methods
  11. Oxidation of dibenzothiophene using the heterogeneous catalyst of tungsten-based carbon nanotubes
  12. Calcined sodium silicate as an efficient and benign heterogeneous catalyst for the transesterification of natural lecithin to L-α-glycerophosphocholine
  13. Synergistic effect between CO2 and H2O2 on ethylbenzene oxidation catalyzed by carbon supported heteropolyanion catalysts
  14. Hydrocyanation of 2-arylmethyleneindan-1,3-diones using potassium hexacyanoferrate(II) as a nontoxic cyanating agent
  15. Green synthesis of hydratropic aldehyde from α-methylstyrene catalyzed by Al2O3-supported metal phthalocyanines
  16. Environmentally benign chemical recycling of polycarbonate wastes: comparison of micro- and nano-TiO2 solid support efficiencies
  17. Medicago polymorpha-mediated antibacterial silver nanoparticles in the reduction of methyl orange
  18. Production of value-added chemicals from esterification of waste glycerol over MCM-41 supported catalysts
  19. Green synthesis of zerovalent copper nanoparticles for efficient reduction of toxic azo dyes congo red and methyl orange
  20. Optimization of the biological synthesis of silver nanoparticles using Penicillium oxalicum GRS-1 and their antimicrobial effects against common food-borne pathogens
  21. Optimization of submerged fermentation conditions to overproduce bioethanol using two industrial and traditional Saccharomyces cerevisiae strains
  22. Extraction of In3+ and Fe3+ from sulfate solutions by using a 3D-printed “Y”-shaped microreactor
  23. Foliar-mediated Ag:ZnO nanophotocatalysts: green synthesis, characterization, pollutants degradation, and in vitro biocidal activity
  24. Green cyclic acetals production by glycerol etherification reaction with benzaldehyde using cationic acidic resin
  25. Biosynthesis, characterization and antimicrobial activities assessment of fabricated selenium nanoparticles using Pelargonium zonale leaf extract
  26. Synthesis of high surface area magnesia by using walnut shell as a template
  27. Controllable biosynthesis of silver nanoparticles using actinobacterial strains
  28. Green vegetation: a promising source of color dyes
  29. Mechano-chemical synthesis of ammonia and acetic acid from inorganic materials in water
  30. Green synthesis and structural characterization of novel N1-substituted 3,4-dihydropyrimidin-2(1H)-ones
  31. Biodiesel production from cotton oil using heterogeneous CaO catalysts from eggshells prepared at different calcination temperatures
  32. Regeneration of spent mercury catalyst for the treatment of dye wastewater by the microwave and ultrasonic spray-assisted method
  33. Green synthesis of the innovative super paramagnetic nanoparticles from the leaves extract of Fraxinus chinensis Roxb and their application for the decolourisation of toxic dyes
  34. Biogenic ZnO nanoparticles: a study of blueshift of optical band gap and photocatalytic degradation of reactive yellow 186 dye under direct sunlight
  35. Leached compounds from the extracts of pomegranate peel, green coconut shell, and karuvelam wood for the removal of hexavalent chromium
  36. Enhancement of molecular weight reduction of natural rubber in triphasic CO2/toluene/H2O systems with hydrogen peroxide for preparation of biobased polyurethanes
  37. An efficient green synthesis of novel 1H-imidazo[1,2-a]imidazole-3-amine and imidazo[2,1-c][1,2,4]triazole-5-amine derivatives via Strecker reaction under controlled microwave heating
  38. Evaluation of three different green fabrication methods for the synthesis of crystalline ZnO nanoparticles using Pelargonium zonale leaf extract
  39. A highly efficient and multifunctional biomass supporting Ag, Ni, and Cu nanoparticles through wetness impregnation for environmental remediation
  40. Simple one-pot green method for large-scale production of mesalamine, an anti-inflammatory agent
  41. Relationships between step and cumulative PMI and E-factors: implications on estimating material efficiency with respect to charting synthesis optimization strategies
  42. A comparative sorption study of Cr3+ and Cr6+ using mango peels: kinetic, equilibrium and thermodynamic
  43. Effects of acid hydrolysis waste liquid recycle on preparation of microcrystalline cellulose
  44. Use of deep eutectic solvents as catalyst: A mini-review
  45. Microwave-assisted synthesis of pyrrolidinone derivatives using 1,1’-butylenebis(3-sulfo-3H-imidazol-1-ium) chloride in ethylene glycol
  46. Green and eco-friendly synthesis of Co3O4 and Ag-Co3O4: Characterization and photo-catalytic activity
  47. Adsorption optimized of the coal-based material and application for cyanide wastewater treatment
  48. Aloe vera leaf extract mediated green synthesis of selenium nanoparticles and assessment of their In vitro antimicrobial activity against spoilage fungi and pathogenic bacteria strains
  49. Waste phenolic resin derived activated carbon by microwave-assisted KOH activation and application to dye wastewater treatment
  50. Direct ethanol production from cellulose by consortium of Trichoderma reesei and Candida molischiana
  51. Agricultural waste biomass-assisted nanostructures: Synthesis and application
  52. Biodiesel production from rubber seed oil using calcium oxide derived from eggshell as catalyst – optimization and modeling studies
  53. Study of fabrication of fully aqueous solution processed SnS quantum dot-sensitized solar cell
  54. Assessment of aqueous extract of Gypsophila aretioides for inhibitory effects on calcium carbonate formation
  55. An environmentally friendly acylation reaction of 2-methylnaphthalene in solvent-free condition in a micro-channel reactor
  56. Aegle marmelos phytochemical stabilized synthesis and characterization of ZnO nanoparticles and their role against agriculture and food pathogen
  57. A reactive coupling process for co-production of solketal and biodiesel
  58. Optimization of the asymmetric synthesis of (S)-1-phenylethanol using Ispir bean as whole-cell biocatalyst
  59. Synthesis of pyrazolopyridine and pyrazoloquinoline derivatives by one-pot, three-component reactions of arylglyoxals, 3-methyl-1-aryl-1H-pyrazol-5-amines and cyclic 1,3-dicarbonyl compounds in the presence of tetrapropylammonium bromide
  60. Preconcentration of morphine in urine sample using a green and solvent-free microextraction method
  61. Extraction of glycyrrhizic acid by aqueous two-phase system formed by PEG and two environmentally friendly organic acid salts - sodium citrate and sodium tartrate
  62. Green synthesis of copper oxide nanoparticles using Juglans regia leaf extract and assessment of their physico-chemical and biological properties
  63. Deep eutectic solvents (DESs) as powerful and recyclable catalysts and solvents for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones
  64. Biosynthesis, characterization and anti-microbial activity of silver nanoparticle based gel hand wash
  65. Efficient and selective microwave-assisted O-methylation of phenolic compounds using tetramethylammonium hydroxide (TMAH)
  66. Anticoagulant, thrombolytic and antibacterial activities of Euphorbia acruensis latex-mediated bioengineered silver nanoparticles
  67. Volcanic ash as reusable catalyst in the green synthesis of 3H-1,5-benzodiazepines
  68. Green synthesis, anionic polymerization of 1,4-bis(methacryloyl)piperazine using Algerian clay as catalyst
  69. Selenium supplementation during fermentation with sugar beet molasses and Saccharomyces cerevisiae to increase bioethanol production
  70. Biosynthetic potential assessment of four food pathogenic bacteria in hydrothermally silver nanoparticles fabrication
  71. Investigating the effectiveness of classical and eco-friendly approaches for synthesis of dialdehydes from organic dihalides
  72. Pyrolysis of palm oil using zeolite catalyst and characterization of the boil-oil
  73. Azadirachta indica leaves extract assisted green synthesis of Ag-TiO2 for degradation of Methylene blue and Rhodamine B dyes in aqueous medium
  74. Synthesis of vitamin E succinate catalyzed by nano-SiO2 immobilized DMAP derivative in mixed solvent system
  75. Extraction of phytosterols from melon (Cucumis melo) seeds by supercritical CO2 as a clean technology
  76. Production of uronic acids by hydrothermolysis of pectin as a model substance for plant biomass waste
  77. Biofabrication of highly pure copper oxide nanoparticles using wheat seed extract and their catalytic activity: A mechanistic approach
  78. Intelligent modeling and optimization of emulsion aggregation method for producing green printing ink
  79. Improved removal of methylene blue on modified hierarchical zeolite Y: Achieved by a “destructive-constructive” method
  80. Two different facile and efficient approaches for the synthesis of various N-arylacetamides via N-acetylation of arylamines and straightforward one-pot reductive acetylation of nitroarenes promoted by recyclable CuFe2O4 nanoparticles in water
  81. Optimization of acid catalyzed esterification and mixed metal oxide catalyzed transesterification for biodiesel production from Moringa oleifera oil
  82. Kinetics and the fluidity of the stearic acid esters with different carbon backbones
  83. Aiming for a standardized protocol for preparing a process green synthesis report and for ranking multiple synthesis plans to a common target product
  84. Microstructure and luminescence of VO2 (B) nanoparticle synthesis by hydrothermal method
  85. Optimization of uranium removal from uranium plant wastewater by response surface methodology (RSM)
  86. Microwave drying of nickel-containing residue: dielectric properties, kinetics, and energy aspects
  87. Simple and convenient two step synthesis of 5-bromo-2,3-dimethoxy-6-methyl-1,4-benzoquinone
  88. Biodiesel production from waste cooking oil
  89. The effect of activation temperature on structure and properties of blue coke-based activated carbon by CO2 activation
  90. Optimization of reaction parameters for the green synthesis of zero valent iron nanoparticles using pine tree needles
  91. Microwave-assisted protocol for squalene isolation and conversion from oil-deodoriser distillates
  92. Denitrification performance of rare earth tailings-based catalysts
  93. Facile synthesis of silver nanoparticles using Averrhoa bilimbi L and Plum extracts and investigation on the synergistic bioactivity using in vitro models
  94. Green production of AgNPs and their phytostimulatory impact
  95. Photocatalytic activity of Ag/Ni bi-metallic nanoparticles on textile dye removal
  96. Topical Issue: Green Process Engineering / Guest Editors: Martine Poux, Patrick Cognet
  97. Modelling and optimisation of oxidative desulphurisation of tyre-derived oil via central composite design approach
  98. CO2 sequestration by carbonation of olivine: a new process for optimal separation of the solids produced
  99. Organic carbonates synthesis improved by pervaporation for CO2 utilisation
  100. Production of starch nanoparticles through solvent-antisolvent precipitation in a spinning disc reactor
  101. A kinetic study of Zn halide/TBAB-catalysed fixation of CO2 with styrene oxide in propylene carbonate
  102. Topical on Green Process Engineering
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