Green biosynthesis of superparamagnetic magnetite Fe3O4 nanoparticles and biomedical applications in targeted anticancer drug delivery system: A review

Green synthesis and environmental application of iron-based nanomaterials and nanocomposite: A review.

Iron oxides are chemical compounds which have different polymorphic forms, including γ-Fe2O3 (maghemite), Fe3O4 (magnetite), and FeO (wustite). Among them, the most studied are γ-Fe2O3 and Fe3O4, as they possess extraordinary properties at the nanoscale (such as super paramagnetism, high specific surface area, biocompatible etc.), because at this size scale, the quantum effects affect matter behavior and optical, electrical and magnetic properties. Therefore, in the nanoscale, these materials become ideal for surface functionalization and modification in various applications such as separation techniques, magnetic sorting (cells and other biomolecules etc.), drug delivery, cancer hyperthermia, sensing etc., and also for increased surface area-to-volume ratio, which allows for excellent dispersibility in the solution form. The current methods used are partially and passively mixed reactants, and, thus, every reaction has a different proportion of all factors which causes further difficulties in reproducibility. Direct active and complete mixing and automated approaches could be solutions to this size- and shape-controlled synthesis, playing a key role in its exploitation for scientific or technological purposes. An ideal synthesis method should be able to allow reliable adjustment of parameters and control over the following: fluctuation in temperature; pH, stirring rate; particle distribution; size control; concentration; and control over nanoparticle shape and composition i.e., crystallinity, purity, and rapid screening. Iron oxide nanoparticle (IONP)-based available clinical applications are RNA/DNA extraction and detection of infectious bacteria and viruses. Such technologies are important at POC (point of care) diagnosis. IONPs can play a key role in these perspectives. Although there are various methods for synthesis of IONPs, one of the most crucial goals is to control size and properties with high reproducibility to accomplish successful applications. Using multiple characterization techniques to identify and confirm the oxide phase of iron can provide better characterization capability. It is very important to understand the in-depth IONP formation mechanism, enabling better control over parameters and overall reaction and, by extension, properties of IONPs. This work provides an in-depth overview of different properties, synthesis methods, and mechanisms of iron oxide nanoparticles (IONPs) formation, and the diverse range of their applications. Different characterization factors and strategies to confirm phase purity in the IONP synthesis field are reviewed. First, properties of IONPs and various synthesis routes with their merits and demerits are described. We also describe different synthesis strategies and formation mechanisms for IONPs such as for: wustite (FeO), hematite (α-Fe2O3), maghemite (ɤ-Fe2O3) and magnetite (Fe3O4). We also describe characterization of these nanoparticles and various applications in detail. In conclusion, we present a detailed overview on the properties, size-controlled synthesis, formation mechanisms and applications of IONPs.

https://www.mdpi.com/1996-1944/13/20/4644/pdf

Magnetic Iron Oxide Nanoparticle (IONP) Synthesis to Applications: Present and Future.

Photocatalytic materials are attracting attention as emerging resources for agricultural applications. This timely review assesses the current developments in the use of biocompatible titanium dioxide (TiO2)-based photocatalytic nanomaterials (TiO2-PN) as models to unravel agricultural growth, harvest, and post-harvest problems. Such developments can lead to technological innovations aimed at addressing the pressing global environmental challenges faced by farming. TiO2-PN have been used as antimicrobial, growth-regulating, and fertilizer-like agents. The promising agricultural research applications of TiO2-PN are highlighted along with a discussion of the main challenges that will need to be overcome to fully understand the roles of TiO2-PN in the sustainable and productive exploitation of land and water for agricultural applications under natural conditions. In particular, rhizosphere internalization, translocation, and plant bioaccumulation pathways of photocatalytic materials from environmental exposition are outlined to illustrate the effect of TiO2 on the agricultural cycle. Nanotoxicology and regulations are also discussed to illustrate the importance of biocompatibility and green synthesis of nanomaterials for safe use in real applications. This overview is focused on motivating and intensifying our understanding of on-site agricultural studies. Complementary biological approaches and structural damage observed by biological transmission electron, scanning electron, and optical microscopies should accelerate the practical contribution of TiO2-PN to sustainable agriculture in conjunction with plant factories and plasma nitrogen fixation technology. Loadings below 10 μg/L of TiO2-PN with a size of 40 nm benefit seed germination and root elongation as well as partially suppressing metal root translocation. However, only approximately 5% of current studies were carried out in real agricultural settings.

Applications of photocatalytic titanium dioxide-based nanomaterials in sustainable agriculture

Three different size tetragonal tin oxide nanoparticles (SnO2 NPs) were synthesized using ascorbic acid as a complexing agent at three different temperatures 170, 500 and 900 °C for 1 h. The synthesized NPs were characterized by using X-ray diffraction (XRD), Transmission Electron Microscope (TEM), Fourier Transform Infrared Spectrophotometer (FT-IR). The optical properties of the synthesized NPs were measured with UV–vis-NIR and fluorescence spectrophotometer. The photocatalytic activity of SnO2 NPs against methylene blue (MB) dye degradation were evaluated with three different size NPs S1, S2 and S3 (3, 11 ± 3 and 27 ± 11 nm) respectively under a multilamp (125 W Hg lamps) photoreactor with UV irradiation towards MB degradation. Smaller size NPs exhibited higher degradation rate within shorter period of time (30 min) than large size NPs (85 min.). Also, photoluminescence (PL) studies under illumination showed that most of the emission energies were within the band gap of SnO2 NPs suggesting Sn interstitials or crystal defects or oxygen vacancy related defects. The present study suggested that the synthesized NPs could be potential photocatalysts against degradation of industrial effluents enriched with different dyes.

Photocatalytic degradation of methylene blue dye by nonconventional synthesized SnO2 nanoparticles

Nanoparticles of Fe3O4 and Fe are chemically synthesized by reduction of Fe(acac)3 using ascorbic acid in controlled condition. It was observed that addition of water during the chemical synthesis process yields Fe3O4 nanoparticles, whereas if the reaction is carried out in absence of water yields Fe nanoparticles—which get oxidized upon exposure to air atmosphere. Fe3O4 (15 ± 5 nm) and Fe/iron oxide nanoparticles (7 ± 1 nm) were successfully synthesized in the comparative study reported herewith. Mechanism for formation/synthesis of Fe3O4 and Fe/iron oxide nanoparticles is proposed herewith in which added water acts as an oxygen supplier. Physico-chemical characterization done by SEM, TEM, EDAX, and XPS supports the proposed mechanism.

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Fe 3 O 4 and Fe Nanoparticles by Chemical Reduction of Fe(acac) 3 by Ascorbic Acid: Role of Water

Magnetite (Fe3O4) nanoparticles were successfully synthesized by ascorbic acid mediated reduction of Fe (acac)3, without using any intentionally added capping agent. Fine tuning of synthesis parameters such as dropping rate of ascorbic acid solution, addition temperature, reflux temperature and time, and concentration of reactants have yielded nanoparticles of size 15±4 nm. Synthesis is observed to be highly reproducible. Possible mechanism for growth of Fe3O4 nanoparticles is suggested. Nanoparticles are characterized for their size, crystallinity and crystal structure, elemental analysis for impurities (if any), and presence of any additional oxide phases – by SEM and TEM, XRD, EDAX and XPS spectroscopy, respectively.

Size Controlled Synthesis of Fe3O4 Nanoparticles by Ascorbic Acid Mediated Reduction of Fe(acac)3 without Using Capping Agent

Synthesis and characterization of graphene-Fe3O4 nanocomposite

Sadhana A. Sawant1, Savita P. Somani2, Arati H. Jadhav3, Ajinkya Nene2, S. K. Omanwar4, and Prakash R. Somani2 ∗ 1Department of Engineering Science, Smt. Kashibai Navale College of Engineering, Vadgaon (Bk.), Pune, Maharashtra, India 2Applied Science Innovations Pvt. Ltd., Vijaynagar, Bld. No. 3, B-14, Dhayari, Near Dhareshwar Mandir, Sinhgad Road, Pune 411041, Maharashtra, India 3National Chemical Laboratory (NCL), Pune, Maharashtra, India 4Department of Physics, Sant Gadge Baba Amravati University, Amravati, Maharashtra, India

Indian Edible Chuna (Calcium Oxide/Hydroxide) as a Green Photocatalyst

Preliminary results of our study related to simultaneous waste water purification by photocatalytic degradation of organic impurity (Methylene Blue dye) and its effects on seed germination are presented here. It is interesting and important to know that complete degradation of the dye occurs within 2 hours and does not adversely affect the seed germination process. It is concluded that waste water purification by photocatalysis and seed germination (agriculture) can be carried out simultaneously, opening a way for advanced agriculture.

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Ajinkya G. Nene

Papers

Fe 3 O 4 and Fe Nanoparticles by Chemical Reduction of Fe(acac) 3 by Ascorbic Acid: Role of Water

Size Controlled Synthesis of Fe3O4 Nanoparticles by Ascorbic Acid Mediated Reduction of Fe(acac)3 without Using Capping Agent

Synthesis and characterization of graphene-Fe3O4 nanocomposite

Indian Edible Chuna (Calcium Oxide/Hydroxide) as a Green Photocatalyst

Simultaneous Waste Water Purification via Photocatalysis and Seed Germination