Synthesis, Properties and Applications of Silica-Coated Magnetite Nanoparticles: A Review

Abstract

Silica-Coated Magnetite nanoparticles (SMNP) recently gained much attractions in biomedical, environmental, construction and nuclear applications. SMNP can overcome the limitations of bare magnetic iron oxide nanoparticles (MNP) such as agglomeration, dissolution and leaching in aqueous and biological system. Silica coating protects the MNP core as well as provides excellent biocompatibility, chemical and thermal stability with higher adsorption capacity of heavy metals and radionuclides. SMNPs are mostly prepared by Modified Stöber method as the simplest route although surface pretreatment or surface modification is needed to avoid formation of large aggregates. Microemulsion method gives excellent size and shape control but needs large quantity of surfactants and solvents. Sonochemical approach provides faster hydrolysis and can prevent agglomeration without any surface pretreatment. Optimal silica coating thickness can provide uniform particles distribution, enough superparamagnetic properties for easy magnetic separation, chemical and thermal stability. Keeping in mind the wide interest in SMNP, this review is designed to report the important information on synthesis, properties and potential applications of SMNP.

Silica Coating of Ferromagnetic Iron Oxide Magnetic Nanoparticles Significantly Enhances Their Hyperthermia Performances for Efficiently Inducing Cancer Cells Death In Vitro

“…Silica coating represents a well-known technique for MNP surface modification concerning the main required features for their biomedical use [29,30]. For instance, the silica shell protects the magnetic core from corrosion and/or oxidation, maintaining its magnetic properties [31,32]; makes the MNPs hydrophilic and provides colloidal stability in biological solutions by avoiding interparticle interactions and agglomeration [33,34]; presents excellent biocompatibility, exhibiting no cell cytotoxicity at concentrations up to 500 µg/mL [35][36][37][38][39]; prevents iron release [40]; and generates high surface area available for further attachment of anticancer drugs or other biologically active moieties [41][42][43][44][45].…”

A Chemiluminescence Sensor for the Detection of α-Fetoprotein and Carcinoembryonic Antigen Based on Dual-Aptamer Functionalized Magnetic Silicon Composite

“…Magnetic silica has the properties of both magnetic and silica materials, such as magnetism, large specific surface area, strong surface adsorption, rich functional groups, and high stability. , Therefore, magnetic silica has been widely used in fields of cell separation, enzyme immobilization, targeted drugs, protein purification, nucleic acid separation, biomarkers, and clinical diagnosis. − Jiang et al prepared monodisperse magnetic polymer/silica hybrid microspheres, which showed excellent adsorption performance for bovine serum albumin . Kong et al prepared asymmetric multilayer-sandwich magnetic mesoporous silica nanobottles and used them as a novel enzyme-driven nanomotor for detection and removal of heavy metal ions .…”