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The aim of the study is an ecotoxicological assessment of magnetite iron oxide-based nanoparticles (NPs), which have risen in popularity in the last decade, on selected terrestrial and aquatic organisms from various levels of the food chain. In the presented study various organisms, from both the terrestrial and aquatic environment, were used as targets for the assessment of NPs ecotoxicity. Plants (radish, oat), marine bacteria (A. fischeri) and crustacean (H. incongruens) were used to represent producers, decomposers, and consumers, respectively. It was found that examined NPs were harmful (to a different degree) to biota from three different trophic levels. Physicochemical characterization (size/morphology, crystallinity, composition, and magnetic properties) of the tested nanoparticles was performed by: transmission electron microscopy, X-ray diffraction, energy dispersive spectroscopy, and Mossbauer spectroscopy, respectively. Phytotoxicity was evaluated according to the OECD 208 Guideline, while acute and chronic toxicity of NPs was conducted using bioassays employing bacteria and crustacea, respectively. The phytotoxicity of all investigated iron oxide-based NPs was dependent on concentration and type of NPs formulation and was measured via biomass, seed germination, root length, shoot height, and content of plant pigments. Increasing the concentration of NPs increased phytotoxicity and mortality of aquatic organisms. Ecotoxicity of iron oxide/silver was dependent on the size and content of silver. Iron oxide NPs coated with nanosilver in a percentage ratio of 69/31 were found to be the most toxic on tested terrestrial and aquatic biota., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

This paper refers to research based on tests completed on the adsorption of heavy metal ions (Pb 2+ , Cu 2+ , Cd 2+ ) from selected natural liquid samples such as apple, tomato, and potato juices using surface-functionalized Mn ferrite nanoparticles (Mn 0.2 Fe 2.8 O 4 ). To determine the most efficient adsorption conditions of these heavy metals, the nanoparticles' surfaces were modified with five different ligands (phthalic anhydride, succinic anhydride, acetic anhydride, 3-phosphonopropionic acid, and 16-phosphonohexadecanoic acid). To evaluate the success of the adsorption process, the resultant liquid samples were examined for the amount of residuals using the flame atomic absorption spectroscopy method. The Mn ferrite particles selected for these tests were first characterized physicochemically by the following methods: transmission electron microscopy, scanning electron microscopy, X-ray diffraction, IR spectroscopy, Mössbauer spectroscopy.

Superparamagnetic iron oxide nanoparticles (SPIONs) and their derivatives (aminosilane and gold-coated) have been widely investigated in numerous medical applications, including their potential to act as antibacterial drug carriers that may penetrate into bacteria cells and biofilm mass. Pseudomonas aeruginosa is a frequent cause of infection in hospitalized patients, and significant numbers of currently isolated clinical strains are resistant to standard antibiotic therapy. Here we describe the impact of three types of SPIONs on the growth of P. aeruginosa during long-term bacterial culture. Their size, structure, and physicochemical properties were determined using transmission electron microscopy, X-ray diffraction analysis, and Fourier transform infrared spectroscopy. We observed significant inhibition of P. aeruginosa growth in bacterial cultures continued over 96 hours in the presence of gold-functionalized nanoparticles (Fe₃O₄@Au). At the 48-hour time point, growth of P. aeruginosa, as assessed by the number of colonies grown from treated samples, showed the highest inhibition (decreased by 40%). These data provide strong evidence that Fe₃O₄@Au can dramatically reduce growth of P. aeruginosa and provide a platform for further study of the antibacterial activity of this nanomaterial.

In the paper, we present three different types of magnetite nanoparticles which were prepared from co-percipitation of iron (II) and (III) chlorides in aqueous solution with and without SiO2 and from thermal decomposition of iron (III) acetylacetonate in nonaqeous solutions. The obtained core-shell nanoparticles were tested in respect of their stability in distilled water, 10% acetic acid, 0.01 M citric acid, 0.9% NaCl and commercial white wine (12% of alcohol). Changes of the nanoparticles were examined by infrared spectroscopy, atomic absorption spectroscopy, transmission electron microscopy, X-ray diffraction and differential scanning calorimetry methods. Modification of magnetic properties was measured by Mössbauer spectroscopy., (Copyright © 2013 Elsevier B.V. All rights reserved.)

In this work magnetite nanoparticles covered by gold and silver shell were obtained. Analyzed particles were modified by two kinds of organophosphorous compounds: 3-phosphonopropionic acid and 16-phosphonohexadecanoic acid. Enzyme immobilization on particles modified in such a way was tested. The crystal structure of obtained nanoparticles was characterized by transmission electron microscopy and X-ray diffraction. Possible changes on the surfaces were analyzed by the use of infrared spectroscopy. Magnetic properties were studied by Mössbauer spectroscopy., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Highlights: [•] Stability of magnetite nanoparticles in environmental solutions was tested. [•] The most aggressive model solutions were determined to be citric acid, acetic acid and white wine. [•] The chosen model solutions dissolve magnetic core (acids) or modifies mostly particle surface (wine). [ABSTRACT FROM AUTHOR]

In presented paper magnetite nanoparticles (MNP), with various types of surface stabilizers has been fabricated. Nanostructures were obtained by thermal decomposition of Fe(acac) 3 precursor in organic solutions. Five types of long-chain carboxylic acids and four types of amines were used for stabilization of nanoparticles. It was also tested, how surfactant concentration influences on the nanoparticles morphology and its properties. Obtained nanoparticles were examined by X-ray diffraction, Transmission Electron Microscopy and Infrared spectroscopy. Magnetic properties of the nanoparticles were tested by Mössbauer spectroscopy and Vibrating Sample Magnetometry. Magnetization and Mössbauer measurements show how stabilizer layer influence the magnetic state of particles. It has been analyzed the importance of the C C chain length, its spatial configuration or compound properties on magnetic state of the particles for few examples. From tested agents as a best, giving most even in shape and well distributed nanoparticles, hexylamine was selected. [ABSTRACT FROM AUTHOR]