Iron-based nanoparticles have been proposed for an increasing number of biomedical or environmental applications although in vitro toxicity has been observed. The aim of this study was to understand the relationship between the redox state of iron-based nanoparticles and their cytotoxicity toward a Gram-negative bacterium, Escherichia coli. While chemically stable nanoparticles (gammaFe2O3) have no apparent cytotoxicity, nanoparticles containing ferrous and, particularly, zerovalent iron are cytotoxic. The cytotoxic effects appear to be associated principally with an oxidative stress as demonstrated using a mutant strain of E. coli completely devoid of superoxide dismutase activity. This stress can result from the generation of reactive oxygen species with the interplay of oxygen with reduced iron species (Fe(II) and/or Fe(0)) or from the disturbance of the electronic and/or ionic transport chains due to the strong affinity of the nanoparticles for the cell membrane.
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http://dx.doi.org/10.1021/es800086f | DOI Listing |
ACS Appl Mater Interfaces
January 2025
Institute of Advanced Wear & Corrosion Resistant and Functional Materials, Jinan University, Guangzhou 510632, China.
As a type of century-old catalyst, the use of iron-based materials runs through the Haber-Bosch process and electrochemical synthesis of ammonia because of its excellent capability, low cost, and abundant reserves. How to continuously improve its catalytic activity and stability for electrochemical nitrogen fixation has always been a goal pursued by scientific researchers. Herein, we develop a free-standing iron-based catalyst, i.
View Article and Find Full Text PDFNanoscale
January 2025
Laboratoire Softmat, Université de Toulouse, CNRS UMR 5623, 118 route de Narbonne, 31062 Toulouse Cedex 9, France.
Hybrid polyionic complexes (HPICs) are colloidal structures with a charged core rich in metal ions and a neutral hydrophilic corona. Their properties, whether as reservoirs or catalysts, depend on the accessibility and environment of the metal ions. This study demonstrates that modifying the coordination sphere of these ions can tune the properties of HPICs by altering the composition of the complexing block or varying formulation conditions.
View Article and Find Full Text PDFAnal Chem
January 2025
Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States.
A novel employment of single particle-inductively coupled plasma-mass spectrometry (SP-ICP-MS) was developed, where a microextraction (ME) probe is used to sample nanoparticles from a surface and analyze them in a single analytical step. The effects of several parameters on the performance of ME-SP-ICP-MS were investigated, including the flow rate, choice of carrier solution, particle size, and the design of the microextraction probe head itself. The optimized ME-SP-ICP-MS technique was used to compare the extraction efficiency (EE, defined as the ratio of particles measured to particles deposited on the surface) of the commercial probe head to a newly designed SP polyether ether ketone (PEEK) probe head.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
Princeton Materials Institute, Princeton University, Princeton, NJ, 08540, USA.
Graphene aerogels (GAs) with engineered architectures are a promising material for applications ranging from filtration to energy storage/conversion. However, current preparation approaches involve the combination of multiple intrinsically-different methodologies to achieve graphene-synthesis and architecture-engineering, complicating the entire procedure. Here, a novel approach to prepare GAs with engineered architectures based on the laser-upcycling of protein biowaste, hemoglobin, is introduced.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
College of Materials, Institute of Artificial Intelligence, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, iChEM, Fujian Key Laboratory of Advanced Materials, College of Energy, Xiamen University, Xiamen 361005, China.
Nickel-iron-based catalysts are recognized for their high efficiency in the oxygen evolution reaction (OER) under alkaline conditions, yet the underlying mechanisms that drive their superior performance remain unclear. Herein, we revealed the molecular OER mechanism and the structure-intermediate-performance relationship of OER on a phosphorus-doped nickel-iron nanocatalyst (NiFeP). NiFeP exhibited exceptional activity and stability with an overpotential of only 210 mV at 10 mA cm in 1 M KOH and a cell voltage of 1.
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