Formation and Application of Core-Shell of FePt-Au Magnetic-Plasmonic Nanoparticles.

Da-Hua Wei,Yuan-Chang Liang,Tei-Kai Lin,Huang-Wei Chang

doi:10.3389/fchem.2021.653718

Abstract

Monodispersed FePt core and FePt–Au core–shell nanoparticles (NPs) have been chemically synthesized in liquid solution and with controllable surface-functional properties. The NP size was increased from 2.5 nm for FePt to 6.5 nm for FePt–Au, which could be tuned by the initial concentration of gold acetate coated onto FePt seeding NPs via a seed-mediated formation of self-assembled core–shell nanostructures. The analyses of the interplanar spacing obtained from the high-resolution transmission electron microscopy (HRTEM), selective electron diffraction pattern (SAED), and x-ray diffraction (XRD) confirmed that both FePt core and Au shell belong to the face-centered cubic (fcc) structure. FePt–Au NPs have a surface plasmon resonance (SPR) peak at 528 nm in the visible optical band region, indicating the red shift compared with the typical theoretical value of 520 nm of pure Au NPs. The surface modification and ligand exchange of FePt–Au was using mercaptoacetic acid (thiol) as a phase transfer reagent that turned the NPs hydrophilic due to the functional carboxyl group bond on the surface of presented multifunctional magnetic–plasmonic NPs. The water-dispersible FePt-based NPs conjugated with biomolecules could reach the different biocompatibility requirements and also provide enough heating response that acted as a potential agent for magnetic fluid hyperthermia in biomedical engineering research fields.

Highlights

The interplanar spacing of 0.235 nm obtained from the high-resolution transmission electron microscopy (HRTEM) image can be ascribed to the adjacent (111) plane of the face-centered cubic structure belonging to the Au shell lattice type
According to the feature contrast, the increase in size and slight change in shape of the FePt NPs coated with Au in the transmission electron microscopy (TEM) and HRTEM images provide the clear evidence that supports the formation of FePt–Au core– shell nanostructured materials based on this present in the Au concentration-dependent self-assembly process
The chemically synthesized core–shell of FePt–Au NPs with monodispersity by using the seed-mediated method is presented in this work, and all material analyses confirmed the formation of the FePt–Au core–shell nanostructure

Summary

Introduction

Hybrid metal nanoparticles (NPs) with a magnetic core and multifunctional shell have been explored extensively owing to their wide-range research applications such as information storage and other biological functions in marker, separation, labeling material, drug delivery, therapy, and biological targeting (Lyon et al, 2004; Caruntu et al, 2005; Piao et al, 2008; Kim et al, 2010; Bao et al, 2016; Kudr et al, 2017; Yang et al, 2018; Chai et al, 2019).

Results

Conclusion