Magneto-fluorescent core-shell supernanoparticles

Abstract

Magneto-fluorescent particles have been recognized as an emerging class of materials that exhibit great potential in advanced applications. However, synthesizing such magnetofluorescent nanomaterials that simultaneously exhibit uniform and tunable sizes, high magnetic content loading, maximized fluorophore coverage at the surface and a versatile surface functionality has proven challenging. Here we report a simple approach for co-assembling magnetic nanoparticles with fluorescent quantum dots to form colloidal magneto-fluorescent supernanoparticles. Importantly, these supernanoparticles exhibit a superstructure consisting of a close-packed magnetic nanoparticle 'core', which is fully surrounded by a 'shell' of fluorescent quantum dots. A thin layer of silica coating provides high colloidal stability and biocompatibility, and a versatile surface functionality. We demonstrate that after surface pegylation, these silica-coated magneto-fluorescent supernanoparticles can be magnetically manipulated inside living cells while being optically tracked. Moreover, our silica-coated magneto-fluorescent supernanoparticles can also serve as an in vivo multi-photon and magnetic resonance dual-modal imaging probe.

Luminomagnetic Silica-Coated Heterodimers of Core/Shell FePt/Fe3O4 and CdSe Quantum Dots as Potential Biomedical Sensor

“…After the heat treatment, the sample silica-coated HNS presents increase in the saturation magnetization value, from 11.1 emu g −1 to 28.2 emu g −1 , without meaningful change in the superparamagnetic behavior, as expected after the annealing process [35]. In a general way, however, the saturation magnetization values of both annealed and nonannealed HNS are high enough to allow the application as theranostic system in biomedical applications [1,15].…”

“…Recently, multifunctional nanomaterials with magnetic and luminescent properties have showed excellent features in potential biomedical applications in diagnosis and therapies, or as unique theranostic platform [1][2][3]. Among the different types of luminomagnetic nanomaterials, the heteronanostructures (HNS) show convenient response in biomedical applications, because its features provide properties related to two or more individual nanostructures in the unique nanomaterial [4][5][6].…”

In vivo biodistribution and behavior of CdTe/ZnS quantum dots

“…TEM specimens were prepared by evaporating one drop of nanocrystal solution on carbon-coated copper grids, according to previous studies. [28][29][30] The size and size distribution data were obtained by counting .100 individual particles using Digital micrograph 3.9.…”

Structure diagram of binary Lennard-Jones clusters

“…Some assemblies are kinetically trapped and their structures depend on the history of supraparticle formation. (This effect can be exploited to tailor certain supraparticle structures [8][9][10][11] ). However, there are experimental protocols of colloidal assembly that are dominated by energy minimization.…”