Novel facets of multifunctional Ag@Fe3O4 core-shell nanoparticles for multimodal imaging applications

Abstract

Biocompatible nanoparticles, with magnetic cores and optically active shells, acting as multifunctional materials with a core size of 6 nm encapsulated in silver shells of varying thickness were synthesized through a novel single phase microemulsion method. Incorporation of silver shells onto the magnetite core enhances the intensity of the highest luminescence peak observed for magnetite by a significant luminescence enhancement factor. A blue photoluminescence peak observed in the visible region of spectrum brightens further with the increase in the thickness of silver shell. The magnetic properties of these core-shell nanomaterials show superparamagnetic behavior at room temperature, which is a mandatory criterion for MRI contrast enhancement agents. The hyperthermic response of synthesized magnetite nanoparticles elevates its temperature to 43 °C in a sharp span of time, which is above the desired temperature for the therapeutic application of these multifunctional nanomaterials. These excellent optical and magnetic properties, of the material having a size range suitable for cellular uptake, make it a potential candidate for both diagnostic and therapeutic uses in biomedical applications.

Janus shaped plasmonic-magnetic silver-magnetite nanostructures for multimodal applications

“…The two maxima for silver-magnetite nanostructure appear at 450 nm and 587 nm with relatively larger intensities indicating an increase in the number of electrons participating in electron transfer from various energy levels due to match in energies between charge transfer band (CTB) of silver and Fe-O states. 13) The silver-magnetite nanoparticles have blue-emission in visible region of electromagnetic spectrum. The particles with blue-emission such as carbon-dots and nanoparticles have been studied to be useful in the detection of abnormal live cells due to their easy detection and identification.…”

“…The coreshell structure is found to have an excellent optical tunability of absorption wavelength along the entire visible and near UV range for a core-shell ratio of 12:1 and 16:1 for gold and silver shell coated magnetite nanoparticles, respectively, for smaller particle size. 12,13) Although, they exhibit superior optical properties but decrease in their magnetization is observed which is due to the shielding of the magnetic core with non-magnetic shell. To overcome this drawback, noble metal integrated magnetic nanoparticles with Janus shape can be taken into account which will possibly have a minor impact on the magnetization values of magnetite nanoparticles.…”

Progress and prospects of magnetic iron oxide nanoparticles in biomedical applications: A review

“…The luminescence of magnetite was efficiently improved by surface plasmon absorption of silver coating without any negative effect on superparamagnetic properties of SPIONs. Consequently, these structures were proposed as multimodal imaging agents and hyperthermia for diagnostic and therapeutic applications 129 …”

“…Consequently, these structures were proposed as multimodal imaging agents and hyperthermia for diagnostic and therapeutic applications. 129 Zinc oxide nanoparticles (ZnO NPs) have been receiving tremendous interest in a number of biomedical applications such as drug delivery and bioimaging. 130,131 ZnO nanomaterials are antibacterial, 69 biocompatible, low toxic, anti-inflammatory, and display in vivo biodegradability.…”

Advances in Magnetic Noble Metal/Iron-Based Oxide Hybrid Nanoparticles as Biomedical Devices

“…Singh and collaborators prepared Ag@Fe 3 O 4 core-shell NPs potentially useful as both multimodal imaging and hyperthermia agents [73]. Results showed that the Ag coating intensifies the emission peak corresponding to blue emission, while the Fe 3 O 4 allows a temperature increase to 40–43 °C in less than 10 minutes of treatment.…”