Rapid Raman Imaging of Stable, Functionalized Nanoshells in Mammalian Cell Cultures

Abstract

Two Raman-active poly(ethylene glycol) (PEG) molecules, one linear (MW 5000) and the other branched (MW 2420), are synthesized to stabilize gold-silica nanoshells in cell culture media and track nanoparticles in mammalian cell cultures. The linear PEG provides greater nanoshell stability in saline solution compared to commercially available PEG-thiol or the branched PEG. Surface enhanced Raman scattering rapidly tracks the probes and provides semiquantitative information regarding particle localization within mouse macrophage (RAW 264.7) and human breast cancer (MCF 7) cell cultures.

SERS Tags: Novel Optical Nanoprobes for Bioanalysis

“…62 Individual nanoshell surfaces offer an easily accessible topology and provide average integrated SERS enhancements similar to those obtained with nanosphere dimers. 50,63 Furthermore, nanoshells have sensitive SPRs on the inner and outer shell radius and can be tuned from the visible to the NIR region. 64−66 The SPRs of hollow Au nanoshells with shell diameters around 40 nm redshift from about 610 to 820 nm by decreasing the shell-wall thickness from 6.8 to 3 nm ( Figure 2B).…”

SERS labels for quantitative assays: application to the quantification of gold nanoparticles uptaken by macrophage cells

“…[4][5][6] Several bright examples about the application of SERS labels in nanobiotechnology and nanomedicine have been reported in recent years and various SERS labels have been developed. 18,[20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] For instance, gold nanoparticles capped with thiol terminated oligonucleotides composed of a Raman active molecule on the inner end and a DNA capture sequence have been used for the multiplexed detection of femtomolar amounts of more than six different DNA sequences in the same microarray. 20 In an analogous microarray set up, gold nanoparticles (AuNPs) with a targeting protein allowed the ultrasensible detection of proteins.…”

Novel Analyte Capture Method for SERS Biodetection

“…The probe uses a two-component protection coating method. One component is Ramanactive, consisting of poly(ethylene glycol) terminated with para-mercaptoaniline (pMA-PEG) to bind the Au and act as a Raman dye (pMA) and imparts particle stability (PEG) 5 . Another component acted as the antigen recognition element (antiIgG for these tests), and was linked to the gold surface via a PEG spacer through coupling between (ortho-pyridyl)disulfide-PEG-Succinimidyl ester (OPSS-PEG-NHS) and primary amines on the antibody 6 .…”