Recent advancement in biogenic synthesis of iron nanoparticles

Green synthesis and characterization of iron nanoparticles synthesized from bioflocculant for wastewater treatment: A review

Nanotechnology is a rapidly expanding field with diverse healthcare, agriculture, and industry applications. Central to this discipline is manipulating materials at the nanoscale, particularly nanoparticles (NPs) ranging from 1 to 100 nm. These NPs can be synthesized through various methods, including chemical, physical, and biological processes. Among these, biological synthesis has gained significant attention due to its eco-friendly nature, utilizing natural resources such as microbes and plants as reducing and capping agents. However, information is scarce regarding the production of iron nanoparticles (FeNPs) using biological approaches, and even less is available on the synthesis of FeNPs employing microbial bioflocculants. This review aims to provide a comprehensive examination of the synthesis of FeNPs using microbial bioflocculants, highlighting the methodologies involved and their implications for environmental applications. Recent findings indicate that microbial bioflocculants enhance the stability and efficiency of FeNP synthesis while promoting environmentally friendly production methods. The synthesized FeNPs demonstrated effective removal of contaminants from wastewater, achieving removal rates of up to 93 % for specific dyes and significant reductions in chemical oxygen demand (COD) and biological oxygen demand (BOD). Additionally, these FeNPs exhibited notable antimicrobial properties against both Gram-positive and Gram-negative bacteria. This review encompasses studies conducted between January 2015 and December 2023, providing detailed characterization of the synthesized FeNPs and underscoring their potential applications in wastewater treatment and environmental remediation.

Recent Advancements in Gallic Acid-Based Drug Delivery: Applications, Clinical Trials, and Future Directions

Gallic acid (GA) is a well-known herbal bioactive compound found in many herbs and foods like tea, wine, cashew nuts, hazelnuts, walnuts, plums, grapes, mangoes, blackberries, blueberries, and strawberries. GA has been reported for several pharmacological activities, such as antioxidant, inflammatory, antineoplastic, antimicrobial, etc. Apart from its incredible therapeutic benefits, it has been associated with low permeability and bioavailability issues, limiting their efficacy. GA belongs to BCS (Biopharmaceutics classification system) class III (high solubility and low probability). In this context, novel drug delivery approaches played a vital role in resolving these GA issues. Nanocarrier systems help improve drug moiety's physical and chemical stability by encapsulating them into a lipidic or polymeric matrix or core system. In this regard, researchers have developed a wide range of nanocarrier systems for GA, including liposomes, transfersomes, niosomes, dendrimers, phytosomes, micelles, nanoemulsions, metallic nanoparticles, solid lipid nanoparticles (SLNs), nanoparticles, nanostructured lipid carriers, polymer conjugates, etc. In the present review, different search engines like Scopus, PubMed, ScienceDirect, and Google Scholar have been referred to for acquiring recent information on the theme of the work. Therefore, this review paper aims to emphasize several novel drug delivery systems, patents, and clinical updates of GA.

Black seed assisted synthesis, characterization, free radical scavenging, antimicrobial and anti-inflammatory activity of iron oxide nanoparticles

Iron nanoparticles comprise a significant class of inorganic nanoparticles, which discover applications in various zones by prudence of their few exciting properties. This study achieved the green synthesis of iron oxide nanoparticles (IONPs) by black cumin seed (Nigella sativa) extract, which acts as a reducing and capping agent. The iron nanoparticles and black cumin extract were synthesized in three different concentrations: (01:01, 02:04,01:04). UV-visible spectroscopy, XRD, FTIR, and AFM characterized the synthesized iron oxide nanoparticles. UV-visible spectra show the maximum absorbance peak of 01:01 concentration at 380 nm. The other concentrations, such as 02:04, peaked at 400 nm and 01:04 at 680 nm, confirming the formation of iron oxide nanoparticles. AFM analysis reveals the spherical shape of iron oxide nanoparticles. The XRD spectra reveal the (fcc) cubic crystal structure of the iron oxide nanoparticles. The FTIR analysis's peaks at 457.13, 455.20, and 457.13 cm-1 depict the characteristic iron nanoparticle synthesis. The black cumin extract-mediated iron oxide nanoparticles show substantial antibacterial, antifungal, antioxidant and anti-inflammatory activity in a dose-dependent manner.

Advances in the Optimization of Fe Nanoparticles: Unlocking Antifungal Properties for Biomedical Applications

In recent years, nanotechnology has achieved a remarkable status in shaping the future of biological applications, especially in combating fungal diseases. Owing to excellence in nanotechnology, iron nanoparticles (Fe NPs) have gained enormous attention in recent years. In this review, we have provided a comprehensive overview of Fe NPs covering key synthesis approaches and underlying working principles, the factors that influence their properties, essential characterization techniques, and the optimization of their antifungal potential. In addition, the diverse kinds of Fe NP delivery platforms that command highly effective release, with fewer toxic effects on patients, are of great significance in the medical field. The issues of biocompatibility, toxicity profiles, and applications of optimized Fe NPs in the field of biomedicine have also been described because these are the most significant factors determining their inclusion in clinical use. Besides this, the difficulties and regulations that exist in the transition from laboratory to experimental clinical studies (toxicity, specific standards, and safety concerns) of Fe NPs-based antifungal agents have been also summarized.

Green synthesis of silver nanoparticles based on the Raphanus sativus leaf aqueous extract and their toxicological/microbiological activities

Silver nanoparticles (AgNPs) have several uses. Many scientists are working on producing AgNPs from plant extracts for use as biomedicines against drug-resistant bacteria and malignant cell lines. In the current study, plant-based AgNPs were synthesized using Raphanus sativus L. (RS) leaf aqua extract. Different concentrations of AgNO₃ were used to optimize the synthesis process of RS-AgNPs from the aqueous leaf extract. Energy-dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscope (AFM), and UV-vis spectroscopy were used to analyze the generated materials. Furthermore, to evaluate the biological properties of the obtained materials, Bacillus subtilis (B. subtilis), Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Candida albicans (C. albicans) pathogen strains were used for the minimum inhibitory concentration (MIC) assays. Subsequently, healthy cell lines (human dermal fibroblast (HDF)) and cancerous cell lines (glioma/U118, Ovarian/Skov-3, and colorectal adenocarcinoma/CaCo-2) were engaged to determine the cytotoxic effects of the synthesized NPs. The cytotoxic and anti-pathogenic potential of AgNPs synthesized by the proposed green approach was investigated. The results were encouraging compared to the standards and other controls. Plant-based AgNPs were found to be potential therapeutic agents against the human colon cancer cell (CaCo-2) and showed strong inhibitory activity on Candida albicans and Staphylococcus aureus growth. The RS-AgNPs generated have highly effective antimicrobial properties against pathogenic bacteria. Our findings also show that green RS-AgNPs are more cytotoxic against cancerous cell lines than normal cell lines. Synthesized nanoparticles with desirable morphology and ease of preparation are thought to be promising materials for antimicrobial, cytotoxic, and catalytic applications.

Biosynthesis of bionanomaterials using Bacillus cereus for the recovery of rare earth elements from mine wastewater

The growing demand for rare earth elements (REEs) increasingly requires secondary resources such as mine wastewater containing high concentrations of REEs, to be used as a source of REEs. The current challenge is how to efficiently recover REEs from this feed source. In this paper, a functional bionanomaterial (FeNPs-EPS) was biosynthesized using Bacillus cereus as a possible means of recovering REEs. This composite was composed of both synthesized iron nanoparticles (FeNPs) and extracellular polymeric substances (EPS). Synthesis of the FeNPs-EPS composite via a one-step biosynthesis was confirmed by materials characterization. The peak in the material's UV-Vis spectra at 511 nm demonstrates the formation of FeNPs-EPS, where 3D-EEM showed that FeNPs-EPS was wrapped predominantly with tryptophan protein-like and humic acid-like substances. In addition, while FTIR indicated that the functional groups present in EPS where virtually identical to those observed in FeNPs-EPS, XPS demonstrated that Fe and O were the major elemental present as both FeO and Fe₂O₃. Zeta potential measurements indicated that FeNPs-EPS had good stability under different pH conditions, where BET analysis supported multilayer adsorption. Finally, on exposure to high concentrations of Eu(III) and Tb(III) in mine wastewater, the synthesized FeNPs-EPS demonstrated strong potential to remove two cations from the wastewater and hence a potentially practical way to efficiently recover REEs from such waste streams.

Optimization of magnetic nano-iron production by Aspergillus flavipes MN956655.1 using response surface methodology and evaluation of their dye decolorizing and antifungal activities

Iron nanoparticles have been biosynthesized by a new Aspergillus flavipes isolate. Size of biosynthesized iron nanoparticles was in a range of 32.7 and 47.6 nm, their surface charge was - 33.5 ± 5.3 and they showed semihard ferromagnetic behavior. Salt concentration, volume of added culture filtrate and pH have been optimized using response surface methodology. A significant effect for the added culture filtrate and a mutual interaction between this factor and the pH has been detected. Model validation results showed 3.3% deviation from the statistically predicted values which reflects the accuracy of the employed model. Optimization process has increased the quantity of iron in the prepared samples and the amount of produced iron nanoparticles to a fourfold. The optimized conditions have stimulated the formation of nanoparticles in a tetrahedron shape rather than the truncated tetrahedron shape without affecting their size or surface charge. The biosynthesized iron nanoparticles have recorded a good decolorization activity for methylene blue. They showed 57 ± 4.3 decolorization percent after 6 h when tested with only 0.1 mg/ml concentration. Moreover, 50 ppm concentration has exerted a detectable antifungal activity against Alternaria solani. This study represents a new competitive green synthesis method for magnetic iron nanoparticle.

Nanomaterials in bioelectrochemical devices: on applications enhancing their positive effect

Electrochemical biosensors and biofuel cells are finding an ever-increasing practical application due to several advantages. Biosensors are miniature measuring devices, which can be used for on-the-spot analyses, with small assay times and sample volumes. Biofuel cells have dual benefits of environmental cleanup and electric energy generation. Application of nanomaterials in biosensor and biofuel-cell devices increases their functioning efficiency and expands spheres of use. This review discusses the potential of nanomaterials in improving the basic parameters of bioelectrochemical systems, including the sensitivity increase, detection lower-limit decrease, detection-range change, lifetime increase, substrate-specificity control. In most cases, the consideration of the role of nanomaterials links a certain type of nanomaterial with its effect on the bioelectrochemical device upon the whole. The review aims at assessing the effects of nanomaterials on particular analytical parameters of a biosensor/biofuel-cell bioelectrochemical device.

Biogenic metal nanoparticles with microbes and their applications in water treatment: a review

Due to their unique characteristics, nanomaterials are widely used in many applications including water treatment. They are usually synthesized via physiochemical methods mostly involving toxic chemicals and extreme conditions. Recently, the biogenic metal nanoparticles (Bio-Me-NPs) with microbes have triggered extensive exploration. Besides their environmental-friendly raw materials and ambient biosynthesis conditions, Bio-Me-NPs also exhibit the unique surface properties and crystalline structures, which could eliminate various contaminants from water. Recent findings in the synthesis, morphology, composition, and structure of Bio-Me-NPs have been reviewed here, with an emphasis on the metal elements of Fe, Mn, Pd, Au, and Ag and their composites which are synthesized by bacteria, fungi, and algae. Furthermore, the mechanisms of eliminating organic and inorganic contaminants with Bio-Me-NPs are elucidated in detail, including adsorption, oxidation, reduction, and catalysis. The scale-up applicability of Bio-Me-NPs is also discussed.

Biologically synthesized iron nanoparticles (FeNPs) from Phoenix dactylifera have anti-bacterial activities

Nanotechnology is a vast field of science with the most vibrant and conspicuous applications. The green synthesis approach is cost-effective, eco-friendly, and produces the most stable metal-based nanoparticles without the use of toxic chemicals. This study presents the green synthesis of iron nanoparticles (FeNPs). For biosynthesis of FeNPs, Phoenix dactylifera extract was used as a reducing agent and iron sulfate heptahydrate (FeSO4·7H2O) was used as a substrate. FeNPs were characterized by different techniques including UV-Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), and nano zeta-sizer analysis. The antimicrobial activity of FeNPs synthesized by using an aqueous extract of Phoenix dactylifera was evaluated against Escherichia coli, Bacillus subtilis, Micrococcus leutus, and Klebsiella pneumoniae. A notable color change from yellow to black confirmed the synthesis of FeNPs. The sharp peak at 450 nm UV-Visible spectroscopy confirmed the synthesis of FeNPs. FTIR showed the presence of O-H and C=C stretching due to the presence of phenol and alkene functional groups. The average size of FeNPs was 6092 d.nm. The results of antimicrobial activity showed that FeNPs exhibit different potential against different bacterial strains with a maximum 25 ± 0.360 zone of inhibition against Escherichia coli. Thus, green synthesized FeNPs could be used as potential antimicrobial agents.

Nanomagnetic approach applied to microalgae biomass harvesting: advances, gaps, and perspectives

Microalgae biomass is a versatile option for a myriad of purposes, as it does not require farmable land for cultivation and due of its high CO₂ fixation efficiency during growth. However, biomass harvesting is considered a bottleneck in the process because of its high cost. Magnetic harvesting is a promising method on account of its low cost, high harvesting speed, and efficiency, which can be used to improve the results of other harvesting methods. Here, we present the state of the art of the magnetic harvesting method. Detailed approaches involving different nanomaterials are described, including types, route of synthesis, and functionalization, variables that interfere with harvesting, and recycling methods of nanoparticles and medium. In addition to discussing the overall perspectives of the method, we provide a guideline for future research.

Seaweed bioactive compounds: Promising and safe inputs for the green synthesis of metal nanoparticles in the food industry

Scientific research on developing and characterizing eco-friendly metal nanoparticles (NPs) is an active area experiencing currently a systematic and continuous growth. A variety of physical, chemical and more recently biological methods can be used for the synthesis of metal nanoparticles. Among them, reports supporting the potential use of algae in the NPs green synthesis, contribute with only a minor proportion, although seaweed was demonstrated to perform as a successful reducing and stabilizing agent. Thus, the first part of the present review depicts the up-to-date information on the use of algae extracts for the synthesis of metal nanoparticles, including a deep discussion of the certain advantages as well as some limitations of this synthesis route. In the second part, the available characterization techniques to unravel their inherent properties such as specific size, shape, composition, morphology and dispersibility are comprehensively described, to finally focus on the factors affecting their applications, bioactivity, potential toxic impact on living organisms and incorporation into food matrices or food packaging, as well as future prospects. The present article identifies the key knowledge gap in a systematic way highlighting the critical next steps in the green synthesis of metal NPs mediated by algae.

A Survey on Analytical Methods for the Characterization of Green Synthesized Nanomaterials

Nowadays, nanotechnologies are well established and the uses of a great variety of nanomaterials show exponential growth. The development of green synthesis procedures experienced a great development thanks to the contribution of researchers of diverse origins. The versatility of green chemistry allows producing a wide range of organic and inorganic nanomaterials with numerous promising applications. In all cases, it is of paramount importance to carefully characterize the resulting nanomaterials because their properties will determine their correct performance to accomplish the function to which they were synthesized or even their detrimental effects like nanotoxicological behavior. This review provides an overview of frequently employed characterization methods and their applications for green synthesized nanomaterials. However, while several different nanoscale materials and their associated green construction methodology are being developed, other important techniques would be extensively incorporated into this field soon. The aim is to encourage researchers in the field to employ a variety of these techniques for achieving an exhaustive characterization of new nanomaterials and for contributing to the development of validated green synthesis procedures.

Accumulation and cellular toxicity of engineered metallic nanoparticle in freshwater microalgae: Current status and future challenges

Metal nanoparticles (MNPs) are employed in a variety of medical and non-medical applications. Over the past two decades, there has been substantial research on the impact of metallic nanoparticles on algae and cyanobacteria, which are at the base of aquatic food webs. In this review, the current status of our understanding of mechanisms of uptake and toxicity of MNPs and metal ions released from MNPs after dissolution in the surrounding environment were discussed. Also, the trophic transfer of MNPs in aquatic food webs was analyzed in this review. Approximately all metallic nanoparticles cause toxicity in algae. Predominantly, MNPs are less toxic compared to their corresponding metal ions. There is a sufficient evidence for the trophic transfer of MNPs in aquatic food webs. Internalization of MNPs is indisputable in algae, however, mechanisms of their transmembrane transport are inadequately known. Most of the toxicity studies are carried out with solitary species of MNPs under laboratory conditions rarely found in natural ecosystems. Oxidative stress is the primary toxicity mechanism of MNPs, however, oxidative stress seems a general response predictable to other abiotic stresses. MNP-specific toxicity in an algal cell is yet unknown. Lastly, the mechanism of MNP internalization, toxicity, and excretion in algae needs to be understood carefully for the risk assessment of MNPs to aquatic biota.