Conventional to green synthesis of magnetic iron oxide nanoparticles; its application as catalyst, photocatalyst and toxicity: A short review

Heterogeneous Iron-Based Catalysts for Organic Transformation Reactions: A Brief Overview

Iron (Fe) is considered to be one of the most significant elements due to its wide applications. Recent years have witnessed a burgeoning interest in Fe catalysis as a sustainable and cost-effective alternative to noble metal catalysis in organic synthesis. The abundance and low toxicity of Fe, coupled with its competitive reactivity and selectivity, underscore its appeal for sustainable synthesis. A lot of catalytic reactions have been performed using heterogeneous catalysts of Fe oxide hybridized with support systems like aluminosilicates, clays, carbonized materials, metal oxides or polymeric matrices. This review provides a comprehensive overview of the latest advancements in Fe-catalyzed organic transformation reactions. Highlighted areas include cross-coupling reactions, C-H activation, asymmetric catalysis, and cascade processes, showcasing the versatility of Fe across a spectrum of synthetic methodologies. Emphasis is placed on mechanistic insights, elucidating the underlying principles governing iron-catalyzed reactions. Challenges and opportunities in the field are discussed, providing a roadmap for future research endeavors. Overall, this review illuminates the transformative potential of Fe catalysis in driving innovation and sustainability in organic chemistry, with implications for drug discovery, materials science, and beyond.

Advancements in nanotechnology for the delivery of phytochemicals

Phytosomes (phytophospholipid complex) are dosage forms that have recently been introduced to increase the stability and therapeutic effect of herbal medicine. Currently, bioactive herbs and the phytochemicals they contain are considered to be the best remedies for chronic diseases. One promising approach to increase the efficacy of plant-based therapies is to improve the stability and bioavailability of their bio-active ingredients. Phytosomes employ phospholipids as their active ingredients, and use their amphiphilic properties to solubilize and protect herbal extracts. The unique properties of phospholipids in drug delivery and their use in herbal medicines to improve bioavailability results in significantly enhanced health benefits. The introduction of phytosome nanotechnology can alter and revolutionize the current state of drug delivery. The goal of this review is to explain the application of phytosomes, their future prospects in drug delivery, and their advantages over conventional formulations. Please cite this article as: Chauhan D, Yadav PK, Sultana N, Agarwal A, Verma S, Chourasia MK, Gayen JR. Advancements in nanotechnology for the delivery of phytochemicals. J Integr Med. 2024; 22(4): 385-398.

Immobilization and Characterization of a Processive Endoglucanase EG5C-1 from Bacillus subtilis on Melamine-Glutaraldehyde Dendrimer-Functionalized Magnetic Nanoparticles

Exploring an appropriate immobilization approach to enhance catalytic activity and reusability of cellulase is of great importance to reduce the price of enzymes and promote the industrialization of cellulose-derived biochemicals. In this study, Fe3O4 magnetic nanoparticles (MNPs) were functionalized with meso-2,3-dimercaptosuccinic acid to introduce carboxyl groups on the surface (DMNPs). Then, melamine-glutaraldehyde dendrimer-like polymers were grafted on DMNPs to increase protein binding sites for the immobilization of processive endoglucanase EG5C-1. Moreover, this dendrimer-like structure was beneficial to protect the conformation of EG5C-1 and facilitate the interaction between substrate and active center. The loading capacity of the functionalized copolymers (MG-DMNPs) for EG5C-1 was about 195 mg/g, where more than 90% of the activity was recovered. Immobilized EG5C-1 exhibited improved thermal stability and increased tolerability over a broad pH range compared with the free one. Additionally, MG-DMNP/EG5C-1 biocomposite maintained approximately 80% of its initial hydrolysis productivity after five cycles of usage using filter paper as the substrate. Our results provided a promising approach for the functionalization of MNPs, enabling the immobilization of cellulases with a high loading capacity and excellent activity recovery.

Green Synthesis of Gold, Silver, Copper, and Magnetite Particles Using Poly(tartaric acid) Simultaneously as Coating and Reductant

Poly(tartaric acid) is a relatively recently described polymer that can be easily synthesized and scaled up from a readily available renewable material (tartaric acid). This article demonstrates its use in a green synthesis of gold nanoparticles, silver nanoparticles, copper particles, and magnetite nanoparticles. In this case poly(tartaric acid) acts both as a reductant and as a coating agent. To our knowledge this is the first green synthesis of several different types of nanoparticles using only one reagent (polytartrate) as both reductant and coating. The resulting particles were analyzed by XRD, TEM/SEM, EDX, FTIR, DLS, zeta-potential, XPS, and UV/VIS spectroscopy. Preliminary studies of the thermal behavior of mixtures of different types of particles with poly(tartaric acid) were also conducted. The obtained particles show different sizes depending on the material, and the coating allows for better dispersibility as well as potential further functionalization, making them potentially useful also for other applications, besides the inclusion in polymer composites.

Green Synthesis of Polylactic acid/Fe3O4@β-Cyclodextrin Nanofibrous Nanocomposite Loaded with Ferulago Angulata Extract as a Novel Nano-biosorbent: Evaluation of Diazinon Removal and Antibacterial Activity

Background

Organophosphate pesticides are one of the most extensively applied insecticides in agriculture. These insecticides persist in the environs and thereby cause severe pollution problems. Iron oxide polymer nanocomposites are wastewater remediation agents synthesized by various methods. When compared to chemical processes, green synthesis using plant extract is thought to be more cost- and environmentally-friendly.

Objectives

This study aimed to evaluate the green synthesis of Fe3O4@β-Cyclodextrin (Fe3O4@β-CD) nanoparticles using Ferulago angulata (F. angulata) methanol extract. These nanoparticles are loaded on polylactic acid (PLA) nanofibrous nanocomposite along with Ferulago angulata extract (2, 4, and, 6wt %) to produce PLA/Fe3O4@β-CD/F. angulata extract nanofibrous nanocomposite as a new nano biosorbent. Furthermore, the antibacterial properties of this compound and its activity in diazinon removal have been evaluated.

Materials and Methods

Fe3O4@β-CD nanoparticles synthesis was performed via co-precipitation method using FeCl3.6H2O and FeCl2.4H2O and β-cyclodextrin, and Ferulago angulata extract. Then polylactic acid/ Fe3O4@β-CD / F. angulate.extract nanofibrous nanocomposite was prepared by the electrospinning method. Energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction analysis (XRD), vibrating sample magnetometer (VSM), and Fourier transform infrared spectroscopy (FTIR) were used to analyze the structure of the nanocomposite. The antibacterial activity of this nanocomposite against several fish and human bacterial pathogens, as well as its effectiveness in diazinon elimination, have been evaluated in the sections that follow.

Results

The nanocomposite structure demonstrated that Fe3O4 nanoparticles were produced and put into the polylactic acid matrix with an average particle size of 40 nm. Furthermore, the results showed that this nanocomposite exhibited removal efficiency of diazinon over 80% after 120 minutes under pH=7 and 2.5 gr.L-1 nanocomposite concentration. Also, this structure showed above 70% antibacterial ability against Bacillus cereus, Staphylococcus epidermidis and 60% antibacterial ability against Streptococcus iniae and Yersinia ruckeri.

Conclusion

Fe3O4 nanocomposite synthesis may be accomplished in a delicate and efficient manner by using Ferulago angulata to produce Fe3O4@-CD nanoparticles. The stability of the nanoparticles was enhanced by combining Ferulago angulata extract with polylactic acid nanofibers to create an antibacterial homocomposition nanocomposite. This device may be used to remove and disinfect diazinon from aqueous media in an environmentally friendly manner.

Construction of magnetically recoverable MnZnFe2O4@Ag3PO4 Z-scheme photocatalyst for rapid visible-light-driven phenol degradation

Visible-light-driven magnetic heterojunction as a promising photocatalysts has received much attention in environmental remediation. In this work, novel Z-scheme heterojunction MnZnFe₂O₄@Ag₃PO₄ (MZFO@APO) magnetic photocatalysts with excellent visible-light-driven photocatalytic activity are successfully constructed and characterized. The photocatalytic activity for phenol degradation is measured, and photodegradation mechanism is investigated with EPR, radical trapping experiments, and LC-MS. It turns out that the heterojunction introduced MZFO exhibits good adsorption effect on visible light and the direct Z-scheme bandgap alignment of MZFO and APO significantly improves charge separation and electron transfer, outperforming that of pure APO. MZFO@APO-40% with 40% APO content shows the rapid photodegradation performance, obtaining a 100% removal efficiency of phenol (25 mg L^-1) after 12-min visible light irradiation, and its kinetic constants are approximately 25.3 and 4.9 times higher than that of P25 TiO₂ and pure APO, respectively. Especially, MZFO@APO-40% also possesses a high magnetic separation property and can be efficiently reused for 5 cycles. Additionally, EPR and radical trapping experiments confirm that h⁺, O₂^-, and ¹O₂ are the main active species in the photocatalytic process. Hydroquinone and small molecular organic acids such as maleic acid and oxalic acid are detected by LC-MS, which further indicates that the pathway of phenol degradation involves hydroxylation, open-ring reactions, and mineralization reactions. The novel addition of MZFO in photocatalyst construction has the potential to promote its application in environmental remediation.

Fabrication of superparamagnetic bovine haemoglobin surface-imprinted core-shell nanocomposite adsorbent via emulsion-free sol-gel polymerization

A new strategy has been developed to fabricate a bovine haemoglobin surface-imprinted core-shell nanocomposite adsorbent, demonstrating superparamagnetism via emulsion-free and sol-gel techniques. The obtained magnetic surface-imprinted polymers (MSIPs) possess a porous core-shell nanocomposite structure with a remarkable imprinted recognition ability for template protein in aqueous medium. The MSIPs display higher affinity, adsorption efficiency and selectivity, for template protein compared to the non-target protein. The morphology, adsorption, and recognition properties of the MSIPs have been evaluated by using several characterisation techniques, such as scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and vibrating sample magnetometry. The results show the average diameter of MSIPs ranging between 400 and 600 nm with a saturation magnetization value of 52.6 emu/g and adsorption capacity of 43.75 mg/g_. And because the obtained MSIPs possessed easily accessible recognition sites and performed fast kinetics for template immobilization, it could achieve equilibrium within 60 min. All this revealed the potential application of this approach as an alternative methodology for the generation of protein imprinted biomaterials.

Core-shell micro/nanocapsules: from encapsulation to applications

Encapsulation is the way to wrap or coat one substance as a core inside another tiny substance known as a shell at micro and nano scale for protecting the active ingredients from the exterior environment. A lot of active substances, such as flavours, enzymes, drugs, pesticides, vitamins, in addition to catalysts being effectively encapsulated within capsules consisting of different natural as well as synthetic polymers comprising poly(methacrylate), poly(ethylene glycol), cellulose, poly(lactide), poly(styrene), gelatine, poly(lactide-co-glycolide)s, and acacia. The developed capsules release the enclosed substance conveniently and in time through numerous mechanisms, reliant on the ultimate use of final products. Such technology is important for several fields counting food, pharmaceutical, cosmetics, agriculture, and textile industries. The present review focuses on the most important and high-efficiency methods for manufacturing micro/nanocapsules and their several applications in our life.

Synthesis of a magnetic polystyrene-supported Cu(II)-containing heterocyclic complex as a magnetically separable and reusable catalyst for the preparation of N-sulfonyl-N-aryl tetrazoles

In this work, a cost-effective, environmentally friendly, and convenient method for synthesizing a novel heterogeneous catalyst via modification of polystyrene using tetrazole-copper magnetic complex [Ps@Tet-Cu(II)@Fe₃O₄] has been successfully developed. The synthesized complex was analyzed using TEM (transmission electron microscopy), HRTEM (high resolution-transmission electron microscopy), STEM (scanning transmission electron microscopy), FFT (Fast Fourier transform), XRD (X-ray diffraction), FT-IR (Fourier transform-infrared spectroscopy), TG/DTG (Thermogravimetry and differential thermogravimetry), ICP-OES (Inductively coupled plasma-optical emission spectrometry), Vibrating sample magnetometer (VSM), EDS (energy dispersive X-ray spectroscopy), and elemental mapping. N-Sulfonyl-N-aryl tetrazoles were synthesized in high yields from N-sulfonyl-N-aryl cyanamides and sodium azide using Ps@Tet-Cu(II)@Fe₃O₄ nanocatalyst. The Ps@Tet-Cu(II)@Fe₃O₄ complex can be recycled and reused easily multiple times using an external magnet without significant loss of catalytic activity.

Waste toner-derived porous iron oxide pigments with enhanced catalytic degradation property

'Wealth from Waste' is an emerging concept, since it leads an effective waste treatment and waste recyclability. On the other hand, cost effective production iron oxide (IO) nanomaterials is still needed to develop, owing to their wide applications. Herein, we proposed a simple direct calcination method to prepare porous IO (Fe₃O₄ and Fe₂O₃) nanomaterials from waste toner powder. Characterization techniques reveal that a structural change happened from Fe₃O₄ to γ-Fe₂O₃ and γ-Fe₂O₃ to α-Fe₂O₃ at the calcination temperature of 500 °C and 700 °C respectively. Consequently, optical (band gap) and magnetic parameters of IO samples were significantly varied. The pigment characteristics of the IO samples were evaluated using Commission Internationale de l'Eclairage (CIE) analysis. IO900 sample has shown good brown-red coloration (L* = 43.11, a* = 13.26 and b* = 5.69) and it also exhibited good stability in acidic and basic conditions. Practical applicability of IO pigments were also tested by mixing with plaster of paris (PP) powder. Further, porous IO samples were also used as catalysts in the reductive degradation of methyl orange (MO) dye in presence of excess sodium borohydride (NaBH₄). IO, prepared at 900 °C exhibited ∼99.9% reduction efficiency within 40 min. Recycling experiments indicated that IO900 possess good stability up to seven cycles. The present porous IO samples will become potential in pigment and environmental remediation.

Biosynthesis of iron oxide nanoparticles for the degradation of methylene blue dye, sulfisoxazole antibiotic and removal of bacteria from real water

Water pollution that is caused by dyes, bacteria and antibiotics, has resulted in a threat to living organisms, animals and humans, hence there is a need to synthesize multifunctional materials that can be used for the degradation of various pollutants. The aim of this study was to synthesize Iron oxide (Fe₃O₄) NPs and test this material for photocatalytic degradation and antibacterial activity. The synthesis of Iron oxide (Fe₃O₄) NPs was conducted using M. burkeana extract and characterised using UV-vis, XRD, BET, SEM, EDS and TGA. The material was then tested for its photocatalytic and antibacterial efficiency against methylene blue dye, antibiotic sulfisoxazole and E. coli and S. aureus bacterial strains. XRD confirmed the formation of Fe₃O₄ NPs. UV-vis gave optical information whereby an excitation at 320 nm and a bandgap of 3.74 eV was noted. The deposition of the phytochemicals onto the Fe₃O₄ NPs was demonstrated using FTIR. From the surface analysis, the morphology of the synthesized NPs was found to be rod like and mesoporous. Upon testing for methylene blue degradation, the Fe₃O₄ NPs were more potent under basic conditions (pH 12) and the O₂ radicals were found to be the species responsible for the degradation. Against sulfisoxazole, a 60% degradation was observed. Lastly, when testing these materials against bacterial strains found in tap, pond, river and sewage water, they were potent in particular against gram positive strains. These results show that at optimum conditions, these materials are able to degrade various pollutants in wastewater.

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Biosynthesis of Fe₃0₄ NPs using M. burkeana for the first time.

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99% and 60% degradation of MB dye and antibiotic SSX, respectively.

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Superoxides were the major species responsible for MB degradation.

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Materials could be reused several times.

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High potency against gram positive strains using real water.

Fabrication and characterization of magnetic nanomaterials for the removal of toxic pollutants from water environment: A review

The success of any sustainable growth represents an advancement of novel approaches and new methodologies for managing any ecological concern. Magnetic nanoparticles have gained recent interest owing to their versatile properties such as controlled size, shape, quantum and surface effect, etc, and outcome in wastewater treatment and pollutant removal. Developments have progressed in synthesizing magnetic nanoparticles with the required size, shape and morphology, surface and chemical composition. Magnetic nanoparticles are target specific and inexpensive compared to conventional treatment techniques. This review insight into the synthesis of magnetic nanoparticles using physical, chemical, and biological methods. The biological method of synthesizing magnetic nanoparticles serves to be cost-effective, green process, and eco-friendly for various applications. Characterization studies of synthesized nanoparticles using TEM, XRD, SARS, SANS, DLS, etc are discussed in detail. Magnetic nanoparticles are widely utilized in recent research for removing organic and inorganic contaminants. It was found that the magnetic nanosorption approach together with redox reactions proves to be an effective and flexible mechanism for the removal of pollutants from waste effluents.

Biogenic Preparation, Characterization, and Biomedical Applications of Chitosan Functionalized Iron Oxide Nanocomposite

Chitosan (CS) functionalization over nanomaterials has gained more attention in the biomedical field due to their biocompatibility, biodegradability, and enhanced properties. In the present study, CS functionalized iron (II) oxide nanocomposite (CS/FeO NC) was prepared using Sida acuta leaf extract by a facile and eco-friendly green chemistry route. Phyto-compounds of S. acuta leaf were used as a reductant to prepare CS/FeO NC. The existence of CS and FeO crystalline peaks in CS/FeO NC was confirmed by XRD. FE-SEM analysis revealed that the prepared CS/FeO NC were spherical with a 10–100 nm average size. FTIR analyzed the existence of CS and metal-oxygen bands in the prepared NC. The CS/FeO NC showed the potential bactericidal activity against E. coli, B. subtilis, and S. aureus pathogens. Further, CS/FeO NC also exhibited the dose-dependent anti-proliferative property against human lung cancer cells (A549). Thus, the obtained outcomes revealed that the prepared CS/FeO NC could be a promising candidate in the biomedical sector to inhibit the growth of bacterial pathogens and lung cancer cells.

Recent Advances in the Preparation of Barium Sulfate Nanoparticles: A Mini-Review

The potential for barium sulphate nanoparticles to be used in a variety of important fields has sparked a lot of attention. Methods for obtaining this material by milling (top-down approach) are not very popular due to the difficulty of controlling the size and shape of particles, as well as changes in their physicochemical properties during milling. More promising is the bottom-up approach, which is the interaction of Ba2+ and SO42− ions in a liquid environment. Direct precipitation is the simplest method; however, it does not allow control of the particle size. Microemulsions, microreactors membrane dispersion, as well as spinning disc reactors are used to overcome drawbacks of direct precipitation and allow control of particle size and shape. This is ensured mainly by intensive controlled micromixing of the precursors with concentrations close to saturated ones. The present review focuses on recent advances in the production of barium sulfate nanoparticles using various approaches, as well as their advantages and limitations. The issues of scaling up the techniques are also considered, and promising methods for obtaining BaSO4 nanoparticles are also discussed.