Dimeric Gold Nanoparticle Assemblies as Tags for SERS‐Based Cancer Detection

Abstract

Herein, a new class of multifunctional materials combining a clustered nanoparticle-based probe is presented for surface enhanced Raman scattering (SERS)-based microscopy and surface functionalization for tissue targeting. Controlled assembly of spherical gold nanoparticles into dimers (DNP-REP) is engineered using a small, rigid Raman-active dithiolated linking reporter (REP) to yield narrow internanoparticle gaps and to strategically generate the "hot spot" while concurrently placing the reporter within the region of highest SERS enhancement. Peptide functionalized DNP-REP materials are highly stable even upon incubation with living cells and show controlled levels of binding and intracellular endocytosis. To demonstrate the functionality of such probes for disease detection, differentially targeted DNP-REPs are incubated over various time points with cultured human glioblastoma cells. Using human glioblastoma cells, the SERS maps of targeted tumor cells show the markedly enhanced signals of the DNP-REP, compared to conventional confocal fluorescence based approaches, especially at low incubation times. Even with as few as 40 internalized DNP-REP, a relatively intense SERS signal is measured, demonstrating the high signal to noise ratio and inherent biocompatibility of the materials. Thus, these Raman reporter-based nanoparticle cluster probes present a promising and versatile optical imaging tool for fast, reliable, selective, and ultrasensitive tissue targeting and disease detection and screening.

Raman spectroscopy: techniques and applications in the life sciences

“…Polarized-SERS using aligned Au nanorods conjugated with antibodies, which were synthesized inside human oral cancer cells, were used to detect diagnostic signatures [308]. SERS dimer NPs with di-thiolated reporters functionalized with peptides were used to control binding and endocytosis, and were used in human glioblastoma cells for cancer targeted Raman imaging [309]. Multiplex SERS particles with several reporters [310,311] or additional fluorescence probes [312] have also been used to identify different cancer cells.…”

Spatially, Temporally, and Quantitatively Controlled Delivery of Broad Range of Molecules into Selected Cells through Plasmonic Nanotubes

“…[ 14 ] The introduction of plasmonic systems in this kind of experiments can be of great interest since it enables the exploitation of Raman spectroscopy that provides a deeper insight into the cellular biochemical environment and its local changing at the molecular level. [15][16][17][18][19] Finally, both chemical and physical methods do not afford precise control over the amount of molecules effectively delivered inside the cell. Moreover, they allow virtually any molecule present in the extracellular fl uid to pass into the cell thus inducing nonspecifi c uptake.…”

Photoluminescence of a Plasmonic Molecule

“…[27][28][29][30] 1 By using single-particle spectroscopy to eliminate sample inhomogeneities encountered in bulk 2 measurements and employing a dimer enrichment procedure to ensure that enough AuNS dimers 3 were measured for a quantitative, statistical analysis, we determined the PL quantum yield of 4 individual AuNSs and strongly coupled AuNS dimers. We found that the PL quantum yield was 5 not affected by the increased electric field of the dimers.…”