Unlabelled: The effect of Zn(2+) on both the kinetic and equilibrium aspects of arsenic adsorption to magnetite nanoparticles was investigated at pH 4.5-8.0. At pH 8.0, adsorption of both arsenate and arsenite to magnetite nanoparticles was significantly enhanced by the presence of small amount of Zn(2+) in the solution. With less than 3 mg/L of Zn(2+) added to the arsenic solution prior to the addition of magnetite nanoparticles, the percentage of arsenic removal by magnetite nanoparticles increased from 66% to over 99% for arsenate, and from 80% to 95% for arsenite from an initial concentration of ∼100 μg/L As at pH 8.0. Adsorption rate also increased significantly in the presence of Zn(2+). The adsorption-enhancement effect of Zn(2+) was not observed at pH 4.5-6.0, nor with ZnO nanoparticles, nor with surface-coated Zn-magnetite nanoparticles. The enhanced arsenic adsorption in the presence of Zn(2+) cannot be due to reduced negative charge of the magnetite nanoparticles surface by zinc adsorption. Other cations, such as Ca(2+) and Ag(+), failed to enhance arsenic adsorption. Several potential mechanisms that could have caused the enhanced adsorption of arsenic have been tested and ruled out. Formation of a ternary surface complex by zinc, arsenic and magnetite nanoparticles is a possible mechanism controlling the observed zinc effect. Zinc-facilitated adsorption provides further advantage for magnetite nanoparticle-enhanced arsenic removal over conventional treatment approaches.
Synopsis: Arsenic adsorption to magnetite nanoparticles at neutral or slightly basic pH can be significantly enhanced with trace amount of Zn(2+) due to the formation of a ternary complex.
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http://dx.doi.org/10.1016/j.watres.2010.06.023 | DOI Listing |
Sci Rep
December 2024
Department of Pharmaceutical Chemistry, Dr. D. Y. Patil Institute of Pharmaceutical Sciences and Research, Pimpri, Pune, India.
The emergence of self-propelling magnetic nanobots represents a significant advancement in the field of drug delivery. These magneto-nanobots offer precise control over drug targeting and possess the capability to navigate deep into tumor tissues, thereby addressing multiple challenges associated with conventional cancer therapies. Here, Fe-GSH-Protein-Dox, a novel self-propelling magnetic nanobot conjugated with a biocompatible protein surface and loaded with doxorubicin for the treatment of triple-negative breast cancer (TNBC), is reported.
View Article and Find Full Text PDFMikrochim Acta
December 2024
State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, 214122, China.
A dual-signal aptamer-based assay utilizing colorimetric and fluorescence techniques was developed for the determination of zearalenone (ZEN). The CdTe quantum dots, serving as the fluorescent signal source, were surface-modified onto FeO@SiO and subsequently functionalized with the aptamer. The COF-Au was modified with complementary chain, which possessed peroxide (POD)-like enzyme properties, and could catalyze the peroxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to ox TMB, resulting in the generation of colorimetric signals.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Personalized Medicine Centre, Almazov National Medical Research Centre, Akkuratova Str. 2, 197341 St. Petersburg, Russia.
This study addresses issues in developing spatially controlled magnetic fields for particle guidance, synthesizing biocompatible and chemically stable MNPs and enhancing their specificity to pathological cells through chemical modifications, developing personalized adjustments, and highlighting the potential of tumor-on-a-chip systems, which can simulate tissue environments and assess drug efficacy and dosage in a controlled setting. The research focused on two MNP types, uncoated magnetite nanoparticles (mMNPs) and carboxymethyl dextran coated superparamagnetic nanoparticles (CD-SPIONs), and evaluated their transport properties in microfluidic systems and porous media. The original uncoated mMNPs of bimodal size distribution and the narrow size distribution of the fractions (23 nm and 106 nm by radii) were demonstrated to agglomerate in magnetically driven microfluidic flow, forming a stable stationary web consisting of magnetic fibers within 30 min.
View Article and Find Full Text PDFJ Mol Graph Model
December 2024
Center of Excellence African on future Energies and Systems Electrochemical (ACE-FUELS), University Federal Technology, PMB 1526, Owerri, State from Imo, Nigeria.
Computational techniques have been used to analyze the molecules of 10-hydroxycoronahydine (HC) and voacangine hydroxyindolenine (VH) molecules with the aim of studying the effect of base and temperature on their interaction mechanisms during synthesis green magnetite nanoparticles. Density functional theory (DFT) descriptors such as: energy gap, overall reactivity descriptors, dipole moment and adsorption energy have all been explored in depth to understand the nature of the interaction. The DFT results showed that the molecules studied (HC and VH) are interactive and stable in an aqueous medium, due to the fact that these molecules have free electronic doublets on the nitrogen atom and the bond of the aromatic ring.
View Article and Find Full Text PDFHeliyon
December 2024
Civil Engineering Department, College of Engineering, University of Sulaimani, Kurdistan Region, Iraq.
This study compares magnetite (Fe3O4) nanoparticles synthesized using Aspergillus elegans extract versus commercially available magnetite nanoparticles, focusing on their efficacy in dye degradation. The biosynthesis of Fe3O4 nanoparticles using fungal extracts offers a sustainable and eco-friendly alternative to conventional chemical methods. The nanoparticles were characterized using various techniques, including UV-Vis spectroscopy, XRD, FTIR, SEM, TEM, DLS, zeta potential, and VSM analysis, to assess their structural, morphological, and magnetic properties.
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