Assembly of Plasmonic and Magnetic Nanoparticles with Fluorescent Silica Shell Layer for Tri-functional SERS-Magnetic-Fluorescence Probes and Its Bioapplications

Abstract

In this study, we report on the fabrication of multilayered tri-functional magnetic-SERS-fluorescence nanoprobes (MF-SERS particles) containing clustered superparamagnetic Fe3O4 nanoparticles (NPs), silver NPs, and a fluorescent silica layer. The MF-SERS particles exhibited strong SERS signals from the silver NPs as well as both superparamagnetism and fluorescence. MF–SERS particles were uptaken by cells, allowing successful separation using an external magnetic field. SERS and fluorescence signals could be detected from the NP-containing cells, and CD44 antibody-conjugated MF-SERS particles selectively targeted MDA-MB-231 cells. Based on these properties, MF-SERS particles proved to be a useful nanoprobe for multiplex detection and separation of cancer cells.

Luminescent Zn (II)-Based Nanoprobes: A Highly Symmetric Supramolecular Platform for Sensing of Biological Targets and Living Cell Imaging

“…The energy gap between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) is mainly in the visible light range. Traditional fluorescent organic dyes were used in living cells (Jun et al, 2012;Herpoldt et al, 2017;Kim et al, 2018) with some disadvantages such as photobleaching, low brightness, and scarce permeability. Biology and nanotechnology both inhabiting the same length scale are designed to move synergically, but the properties of the material can be dramatically altered when one or more dimensions are reduced to the nanoscale.…”

Optical-Based (Bio) Sensing Systems Using Magnetic Nanoparticles

“…These improvements can be achieved using MNPs or magnetic nanocomposites because of their unique properties such as strong superparamagnetic property, low toxicity, biocompatibility, easy preparation, and high adsorption ability. As outlined in Table 2, MNPs in SERS analysis have been used for the detection of proteins [65][66][67][68], cells [69][70][71], toxins [72], drugs [73,74], microorganisms [75][76][77][78], illegal additives [79,80], antigens [81,82], pesticides [83], and genes [84,85]. As mentioned above, gold (Au) nanostructures in the manufacture of SERS substrates are one of the most widely used metallic nanostructures for the plasmonic substrate.…”

Synthesis and Application of Silica-Coated Quantum Dots in Biomedicine

“…Nanotechnology has made significant contributions to the development of modern society and is currently receiving considerable attention as a result of its potential to break through current stagnation and open up new horizons for technological advancement [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. Quantum dots (QDs) are one type of nanomaterial that has been studied intensively over the last 30 years, and both significant and continuous advances in their domain have been made since their introduction in the 1980s [ 10 ].…”