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Green Synthesis of Iron Nanomaterials and its Mechanism
Published in Piyal Mondal, Mihir Kumar Purkait, Green Synthesized Iron-based Nanomaterials, 2023
Piyal Mondal, Mihir Kumar Purkait
Iron nanoparticles (Fe NPs) exhibit superb dimensional stability, nontoxicity and have an affinity to form oxides. Apart from having a high surface area, electrical and thermal conductivity, Fe NPs also possess magnetic properties and are known as magnetic nanoparticles (Arabi et al., 2016). Superparamagnetism is a unique consequence of magnetic nanoparticles. It is observed in ferromagnetic or ferrimagnetic nanomaterials, only when the size and number of domains, are both adequately small, broadly between 10 and 150 nm in diameter depending on the material (Clemons et al., 2019). At these extreme sizes, they become a single domain magnetic material that has no hysteresis loop; also, their magnetization can randomly flip direction under the influence of temperature (Frenkel and Doefman, 1930). Iron nanoparticles that exhibit superparamagnetism are termed as superparamagnetic iron oxide nanoparticles (SPIONs), and find wide application in the biomedical field.
Cellulose-Based Nanoadsorbents for Wastewater Remediation
Published in Maulin P. Shah, Removal of Refractory Pollutants from Wastewater Treatment Plants, 2021
Garima Kumari, Eder Lima, Kulvinder Singh, Nitesh Kumar, Anupam Guleria, Dinesh Kumar, Ashish Guleria
Ionic liquids have been used for the preparation of magnetic cellulose nanocomposites and these nanocomposites have been utilized for wastewater remediation. Xiong et al. synthesized magnetic nanocomposites of cellulose–iron oxide nanoparticles by co-precipitation using 1-butyl-3-methylimidazolium chloride ionic liquid as a co-solvent for cellulose and iron salt [49]. It was found that synthesized magnetic nanocomposites exhibited a superparamagnetic behavior, were sensitive under an external magnetic field, and used a nanoadsorbent in water treatment. Magnetic nanocomposites were used for the removal of Pb(II) and methylene blue from water bodies and displayed excellent adsorption efficiency as compared with other reported magnetic materials. The adsorption capacity of the magnetic nanocomposites for the removal of Pb(II) metal ions were 21.5 mg g−1. Furthermore, the prepared magnetic nanoadsorbent could be efficiently recycled and reused by applying an external magnetic field. Ionic liquids have the ability for green and size controlled synthesis of cellulose nanopartilces.
Bacterial Detection with Magnetic Nanoparticles
Published in Klaus D. Sattler, st Century Nanoscience – A Handbook, 2020
Nayeem A. Mulla, Raghvendra A. Bohara, Shivaji H. Pawar
The integration of bioconjugate MNPs with different analytical methods has paved a new path for bacteria, protein, and cancer cell sensing, purification, and quantitative analysis. The scope of superparamagnetic nanoparticles in many technological applications like magnetic storage media, biosensing applications, and medical applications caused this field to develop intensively [54]. In the absence of an external magnetic field, the overall magnetization value of superparamagnetic nanoparticles is randomized to zero. Such fluctuations in magnetization direction result in minimization of the magnetic interactions between any two NPs in the dispersion, making the dispersion stable in physiological solutions and facilitating NP coupling with biological agents [55]. When exposed to an external magnetic field, these MNPs align along the direction of magnetic field, achieving magnetic saturation at a magnitude that far exceeds any of the known biological entities. Due to this unique property of MNPs, detection of the MNP-containing biological samples is enhanced on manipulation of these biological samples with an external magnetic field [56].
A review on magnetic polymeric nanocomposite materials: Emerging applications in biomedical field
Published in Inorganic and Nano-Metal Chemistry, 2023
Polymer nanocomposites exhibiting superparamagnetic behavior have been recognized as a promising tool to achieve targeted drug delivery using external magnetic field for treating complex diseases. Release of a therapeutic agent at specific site and rate is achieved by means of composite nanoparticles, consisting of the carrier, the bound, or encapsulated bioactive payload and surface modifiers. Chen et al.[207] synthesized a biocompatible magnetic nanocomposite of silica, iron oxide, and polymethacrylic acid and used anticancer drug doxorubicin as model drug. A drug loading efficiency of 105 ± 8 μg/mg of drug carrier was reported. Kappa carrageenan-g-poly(acrylic acid)/SPION nanocomposite was exploited as targeted drug delivery system for release of the drug deferasirox. The composite was also found effective as an in vitro antibacterial agent. Doxorubicin delivery was also evaluated by[208] using a poly(ethyleneglycol)-block-poly(4-vinylbenzylphosphonate) block copolymer to synthesize and characterize doxorubicin-containing PEG-ylated iron oxide nanoparticles, as a possible nano carrier for magnetically mediated drug delivery. In vivo studies showed that this compound was efficiently taken up by the C26 cancer cells via the endocytosis pathway and reduced the cell viability.
Immobilization of horseradish peroxidase on lysine-functionalized gum Arabic-coated Fe3O4 nanoparticles for cholesterol determination
Published in Preparative Biochemistry & Biotechnology, 2021
Morteza Varamini, Hajar Zamani, Hale Hamedani, Sepide Namdari, Banafsheh Rastegari
Herein, the new HRP supporting system were introduced based on superparamagnetic nanoparticles which is supported with solvent stable natural polymer, gum Arabic. The superparamagnetic nanoparticles were produced by co-precipitation method and were coated with gum Arabic. Besides, lysine was added to the MNPs as a linker to provide both, enzyme flexibility and more amine residues for glutaraldehyde-mediated HRP immobilization, after oxidation of gum Arabic with sodium periodate. This method was environmentally friendly, low-cost, easy to operate and highly efficient. The horseradish peroxidase was immobilized on the support by covalent bonding, and the optimum conditions were investigated. Based on obtained results, the HRP@GA-MNPs were relatively more stable than free HRP toward the denaturation in alkaline pH, heat, presence of Hg2+ ions, organic solvents and detergent conditions. Moreover, the reusability of immobilized enzymes was found ideal since it retained 60% of its initial activity after 8 cycles using TMB as a chromogen with sensitive detection of cholesterol on serum samples. Also the possibility of co-immobilization of both HRP and ChOx on GA-MNPs provide a new window sights into the development of solvent stable, low cost cholesterol biosensor which will be discussed in future research.
Surface coverage and size analysis of redispersed nanoparticles by image processing
Published in Particulate Science and Technology, 2021
Yaowarat Sirisathitkul, Pharunee Sarmphim, Chitnarong Sirisathitkul
Nanoparticles synthesized from chemical routes likely differ in sizes. To prevent further aggregation, such polydisperse nanoparticles are commonly stabilized by surface-modification and dispersion in organic solvents (Kowalczyk et al. 2011; Rashad et al. 2018; Koo et al. 2019). However, the surfactants tend to degrade and the nanosuspension concentration is increased by solvent evaporation after a prolonged storage (Eberbeck et al. 2006). Moreover, collisions between nanoparticles are increased with the thermal agitation leading to aggregations (Iijima and Kamiya 2009). The increased size distribution affects the self-assembly and utility of nanoparticles. Only monodisperse nanoparticles are able to self-assemble into long-range ordered monolayer and superlattices on liquid (Lotito and Zambelli 2017; Tan et al. 2018) and solid substrates (Wang et al. 2014). For applications of magnetic nanoparticles in biomedicine, the size must be in the superparamagnetic regime coupled with the good dispersion (Mehta 2017). To reduce the size distribution and improve the dispersion, nanoseparation techniques have been implemented including chromatography, electrophoresis, membrane filtration, extraction, selective precipitation and centrifugation (Kowalczyk et al. 2011; Mori 2015). The centrifugation is also useful in classifying aggregated particles for the redispersion.