Simple and Green Synthesis of Nitrogen‐Doped Photoluminescent Carbonaceous Nanospheres for Bioimaging

A red-emitting phosphor Na3AlF6:Mn4+: Green synthesis, optical characteristics, thermal stability and application in high-performance warm WLED

The oxidation of cyclohexanone and/or cyclohexanol to adipic acid (AA) was performed at 90 °C with a reaction time of 20 h, in the presence of H2O2 as oxidant and transition metal substituted ammonia polyoxometalates of formula, (NH4)xHyMzPMo12O40 (M: Fe, Co, or Ni, and x = 2.5 or 2.28) as catalysts. The catalytic results showed that the AA yield is sensitive to the transition metal nature and to the reaction conditions (sample weight and substrate amount). The (NH4)2.29H0.39Co0.16PMo12O40 was found to be the better catalytic system toward AA synthesis from cyclohexanone oxidation, with 40% of AA yield

A simple and green synthesis protocol has been employed to get Ca-ada (calcium-adamantanecarboxylate), the precursor to a hybrid organic–inorganic composite material for high temperature CO2 capture applications.

IntroductionThe coronavirus disease 2019 (COVID-19) pandemic has caused a global health crisis. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly contagious virus that can cause severe respiratory illness. There is no specific treatment for COVID-19, and the development of new drugs is urgently needed.Problem statementThe SARS-CoV-2 main protease (Mpro) enzyme is a critical viral enzyme that plays a vital role in viral replication. The inhibition of Mpro enzyme can be an effective strategy for developing new COVID-19 drugs.MethodologyAn efficient operationally simple and convenient green synthesis method had been done towards a series of novel spiro-N-(4-sulfamoylphenyl)-2-carboxamide derivatives, in ethanol at room temperature in green conditions, up to 90% yield. The molecular structures of the synthesized compounds were verified using spectroscopic methods.The title compounds were subjected to in silico analysis, including Lipinski’s rule and ADMET prediction, in addition to pharmacophore modeling and molecular docking against the active site of SARS-CoV-2 target main protease (Mpro) enzyme (6LU7). Furthermore, both of the top-ranked compounds (5 and 6) and the standard Nirmatrelvir were subjected to DFT analysis.FindingsThe synthesized compounds exhibited good binding affinity to SARS-CoV-2 Mpro enzyme, with binding energy scores ranging from − 7.33 kcal/mol (compound 6) and − 7.22kcal/mol (compound 5) to − 6.54 kcal/mol (compounds 8 and 9). The top-ranked compounds (5 and 6) had lower HOMO–LUMO energy difference (ΔE) than the standard drug Nirmatrelvir. This highlights the potential and relevance of charge transfer at the molecular level.RecommendationThese findings suggest that the synthesized spiro-N-(4-sulfamoylphenyl)-2-carboxamide derivatives could be potential candidates for COVID-19 drug development. To confirm these drugs' antiviral efficacy in vivo, more research is required. With very little possibility of failure, this proven method could aid in the search for the SARS-CoV-2 pandemic's desperately needed medications.Graphical abstract

Adsorption is an effective technology widely used in the removal of radioactive and other heavy metal ions, the adsorbent plays critical role and development of novel adsorbents is being in urgent demand. In this work, phytic acid (PA)‐modified melamine sponge (MS) adsorbent MS@PDA@PA is prepared conveniently in green solvent water. A wide spectrum of metal ions including radioactive uranyl and transition heavy metal ions can be effectively adsorbed by the MS@PDA@PA due to non‐selectivity of phosphoric acid groups in PA. Different factors including pH of aqueous solution, contact time, and initial concentration of ions on the effect of adsorption of the resultant materials are investigated in detail, and the maximum adsorption capacities for U(VI), Pb(II), Cu(II), Cr(III) are 166.7, 168.5, 114.3, and 101.0 mg g −1 respectively at 298 K. It is notable that the MS@PDA@PA is nonflammable due to employment of MS as frame material, and the thermal stability is even improved after incorporation of PA, greatly reduce the risk of the adsorbent in the processes of storage and usage. The green yet simple synthesis and fire resistance of MS@PDA@PA make it a competitive material for practical treatment of wastewater consisting of toxic metal ions.

By understanding the rampant infections of Mycobacterium tuberculosis (Mtb) and inflammations caused due to the generation of radical species during the Mtb infection, a series of (E)-2-(2-allylidenehydrazinyl)thiazole derivatives, with dual-action properties, was designed. The molecules were designed with a considerable variation in LogP, one of the critical parameters in physicochemical properties, and analyzed for their drug-likeness. For the synthesis, a simple, green, and multicomponent one-pot synthesis method was developed. The in vitro inhibition potentials were evaluated against Mtb H37 Rv by the microplate Alamar Blue assay. The results reveal that compound 6 was potent, with a MIC value of 6.5 µg/ml, and showed better interactions with the KasA protein with binding free energy (ΔG) of -9.4 kcal/mol. Also, the radical scavenging properties were studied to establish the dual-action properties of the molecules. Compound 9 exhibited promising antioxidant and nitric oxide radical scavenging activities, with 81.7% and 81.0%, respectively, at 1,000-μg/ml concentration.

In this work, a simple green synthesis method of the novel metal-organic framework (MOF) nanocomposite PCN-224/Au-NPs (Au-NPs = gold nanoparticles) is described. In this regard, initially, PCN-224 was synthesized. Afterward, in a single-step, one-pot procedure, under visible-light irradiation, Au-NPs were fabricated on PCN-224. The cytotoxicity effect of the synthesized PCN-224/Au-NPs nanocomposite was investigated in human colon cancer cells. Determination of the apoptosis induction was done by the Annexin- V/propidium iodide flow cytometry method. Besides, to ascertain the biocompatibility of the synthesized sample, the cytotoxicity of PCN-224/Au-NPs was evaluated on the human embryonic kidney (HEK)-293 cell line. The substantial anticancer activity with the biocompatibility of the structure, the green facile synthesis, and the MOF surface of the synthesized nanocomposite make it special for utilization in therapeutic applications.

The green synthesis rGO/Fe3O4/PANI nanocomposites for enhanced electromagnetic waves absorption

Molybdenum/graphene – Based catalyst for hydrogen evolution reaction synthesized by a rapid photothermal method

This work analyzes the production of a hydrogel composed of mucilage from the cactus Opuntia ficus-indica (OFI) and sodium alginate. In obtaining the new material, green synthesis was used, free of chemical compounds, and applied in the treatment of textile effluent for the adsorption of methylene blue (MB). The hydrogel was characterized by FT-IR, XRD, SEM, and zeta potential. The swelling study showed a maximum value of 262% at pH 6.0. Adsorption studies revealed a maximum adsorptive capacity of 7.21 mg g-1 in 400 min at 298 K. Furthermore, the experimental data showed better fit to the pseudo-second order and Langmuir models for kinetic and isothermal studies, respectively. The adsorptive process showed spontaneous and exothermic behavior as well as a chemisorptive nature. It is noteworthy that in the studies conducted at a higher concentration of the contaminant, the maximum adsorption was 760 mg g-1. The reuse of the hydrogel was effective for five cycles, maintaining the adsorption of approximately 50% MB removal. Therefore, the biodegradable hydrogel is a material that contributes to the environment, is low cost, with simple synthesis, and is a promising new material for large-scale applications, considering its sustainable character and high efficiency in the adsorption of MB in aqueous solution.

Carbon quantum dots derived from polysaccharides: Chemistry and potential applications

Green synthesis, an emerging field in bionanotechnology, refers to the utilization of non-toxic, biologically safe, and eco-friendly substances for the synthesis of desired materials. It provides both economic and environmental benefits along with simple, cost-effective, and reproducible synthesis approaches that result in the development of stable materials. The green synthesis approaches use living biotemplates, including plants and different microorganisms such as viruses, bacteria, fungi, algae, and actinomycetes. The various metabolites present in different parts of the plants, such as leaves, fruits, seeds, flower, and others, serve as the reducing and stabilizing agents. At the same time, the diverse surface chemistry of microorganisms enables them to convert different substrates into a variety of nanomaterials. This review briefly describes the concept of 'green synthesis' and provides an overview of controlled and green synthesis of nanomaterials using the plants and microbial cells as biotemplates. It also discusses the effect of different reaction conditions such as temperature, pH, reaction time, precursor concentration, and the post-synthesis processing of nanoparticles (NPs) on the material properties. It further describes the applications of different NPs in pharmaceutical and environment sectors by considering their diverse antimicrobial, anticancer, antioxidant, antiviral, antimalarial, reduction, and catalytic properties. Finally, it describes various future perspectives of nanomaterials to broaden the understanding of their synthesis mechanism and expand their applications to other fields.

Green and simple synthesis of poly (catechol-tetraethylenepentamine)@aminopropyl-modified silica composite for removing toxic Cr(VI)

Green and simple synthesis strategies have gained tremendous popularity for the production of anisotropically-shaped noble metallic nanoparticles. The long-term stability of the produced particles, the short timescale of the target reaction(s), as well as the use of non-toxic chemicals, are pivotal features of a useful green procedure. Herein we describe a simple and convenient wet-chemical approach to synthesize stable, non-toxic and water-soluble small gold nanotriangles (GNTs) and gold nanospheres (GNSs) in one step at room temperature, using Tween 20 and Tween 80, respectively. A high level of purity and monodispersity was obtained for the GNTs, in addition to an excellent colloidal stability of both GNTs and GNSs in media exhibiting a high ionic strength and over a wide pH range. The presented strategy, which exploits the dual functional properties of Tween as a co-reducing and stabilizing agent, eliminates the presence of hazardous chemicals such as toxic surfactants, hazardous organic solvents and harsh reducing agents during the synthesis process, and hence could pave the way for the facile usage of the spherical and triangular gold nanoparticles for clinical or biological applications. The resulted particles were characterized by UV-Vis spectroscopy, dynamic light scattering and transmission electron microscopy.

Binding imidazoles to amino acids is an interesting synthetic challenge due to the structural particularities of each one. This research found an attractive and simple (almost green) synthesis route to develop two types of imidazoles anchored to amino acids valine and phenylalanine. FT-IR and 1HNMR support this synthetic route.