Abstract
The combined optical and magnetic properties of magnetic-plasmonic core-shell nanoparticles (NPs) makes them ideal candidates for many applications in biomedical fields. Plasmonic properties of the shell gives rise to Surface Enhanced Raman Scattering (SERS) that can be utilized for sensitive detections, while magnetic properties are useful for magnetic separation and magnetic guided delivery. The plasmonic properties of the shell depends on both the size and shape of the core and shell, and this property, in principle, can be calculated using the Discrete Dipole Approximation (DDA) method. However, since the DDA is an approximation method, its accuracy to calculate the plasmonic properties of the shell, especially the near-field enhancement relevant to SERS, has not been examined carefully. We present a systematic test on the accuracy of the DDA to calculate the plasmonic properties in terms of both the extinction spectra and the near-field enhancement of the magnetic-plasmonic core-shell NPs. Accuracy of the DDA method was first investigated in comparison to Mie theory results for spherical core-shell NPs, since Mie theory gives the exact solution to spherical shaped particles. DDA calculations were further extended to core-shell nanoparticles with octahedral cores. We elucidate convergence of the DDA results by considering the effects of dipole distance and shell thickness in regard to the NP spectral properties. This work validates application of the DDA methods for calculating electrodynamic properties of core-shell NPs and highlights plasmonic properties of core-shell with non-spherical cores.
Highlights
Magnetic-plasmonic core shell nanoparticles (NPs) possess dual magnetic and plasmonic properties and have widespread applications in biomedical fields.1–5 The magnetic cores such as iron oxide (IO) are greatly desired for applications such as magnetic separation, magnetic resonance imaging or magnetic guided drug delivery
Surface sites in the Discrete Dipole Approximation (DDA) calculations are defined as any medium lattice site where one of its nearest neighbors is occupied by the particle
A smaller dipole distance corresponds to a finer grid spacing, and an overall higher number of dipoles used in the DDA calculations, which, usually leads to a more accurate result
Summary
Magnetic-plasmonic core shell nanoparticles (NPs) possess dual magnetic and plasmonic properties and have widespread applications in biomedical fields. The magnetic cores such as iron oxide (IO) are greatly desired for applications such as magnetic separation, magnetic resonance imaging or magnetic guided drug delivery. Magnetic-plasmonic core shell nanoparticles (NPs) possess dual magnetic and plasmonic properties and have widespread applications in biomedical fields.. Magnetic-plasmonic core shell nanoparticles (NPs) possess dual magnetic and plasmonic properties and have widespread applications in biomedical fields.1–5 The magnetic cores such as iron oxide (IO) are greatly desired for applications such as magnetic separation, magnetic resonance imaging or magnetic guided drug delivery. Depending on the experimental setup, the relevant data associated with the SERS intensity is either the enhancement R(ω) averaged over the particle surface , or the maximum Rmax(ω) in the case of single molecule SERS. Both quantities are of interest to examine.. Both quantities are of interest to examine. SERS detection using such magneticplasmonic core-shell NPs have many promising applications in nanomedicines.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
