Differentiation of MCF-7 tumor cells from leukocytes and fibroblast cells using epithelial cell adhesion molecule targeted multicore surface-enhanced Raman spectroscopy labels.
Identification of tumor and normal cells is a promising application of Raman spectroscopy. The throughput of Raman-assisted cell sorting is limited by low sensitivity. Surface-enhanced Raman spectroscopy (SERS) is a well-recognized candidate to increase the intensity of Raman signals of cells. First, different strategies are summarized to detect tumor cells using targeted SERS probes. Then, a protocol is described to prepare multicore-SERS-labels (MSLs) by aggregating gold nanoparticles, coating with a reporter molecule and a thin silver shell to further boost enhancement, encapsulating with a stable silica layer, and functionalizing by epithelial cell adhesion molecule (EpCAM) antibodies. Raman, dark field and fluorescence microscopy proved the specific and nonspecific binding of functionalized and nonfunctionalized MSLs to MCF-7 tumor cells, leukocytes from blood, and nontransformed human foreskin fibroblasts. Raman imaging and dark field microscopy indicated no uptake of MSLs, yet binding to the cellular membrane. Viability tests were performed with living tumor cells to demonstrate the low toxicity of MSL-EpCAM. The SERS signatures were detected from cells with exposure times down to 25 ms at 785-nm laser excitation. The prospects of these MSLs in multiplex assays, for enumeration and sorting of circulating tumor cells in microfluidic chips, are discussed.
Leibniz Institute of Photonic Technology, Albert-Einstein-Street 9, Jena 07745, Germany.
Isabel
I
Freitag
Leibniz Institute of Photonic Technology, Albert-Einstein-Street 9, Jena 07745, GermanybUniversity of Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Helmholtzweg 4, Jena 07743, Germany.
Christian
C
Matthäus
Leibniz Institute of Photonic Technology, Albert-Einstein-Street 9, Jena 07745, Germany.
Andrea
A
Csaki
Jena University Hospital, Department of Haematology and Medical Oncology, Erlanger Allee 101, Jena 07747, Germany.
Joachim H
JH
Clement
Leibniz Institute of Photonic Technology, Albert-Einstein-Street 9, Jena 07745, GermanybUniversity of Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Helmholtzweg 4, Jena 07743, Germany.
Dana
D
Cialla-May
Leibniz Institute of Photonic Technology, Albert-Einstein-Street 9, Jena 07745, GermanybUniversity of Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Helmholtzweg 4, Jena 07743, Germany.
Karina
K
Weber
Leibniz Institute of Photonic Technology, Albert-Einstein-Street 9, Jena 07745, Germany.
Christoph
C
Krafft
Leibniz Institute of Photonic Technology, Albert-Einstein-Street 9, Jena 07745, GermanybUniversity of Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Helmholtzweg 4, Jena 07743, Germany.
Jürgen
J
Popp
D000906:Antibodies / Q000737:chemistry / Q000276:immunology*; D000951:Antigens, Neoplasm / Q000737:chemistry / Q000276:immunology*; D015815:Cell Adhesion Molecules / Q000737:chemistry / Q000276:immunology*; D003937:Diagnosis, Differential; D000071858:Epithelial Cell Adhesion Molecule; D005347:Fibroblasts / Q000166:cytology / Q000276:immunology; D006046:Gold / Q000737:chemistry; D006801:Humans; D007962:Leukocytes / Q000166:cytology / Q000276:immunology; D061986:MCF-7 Cells; D053768:Metal Nanoparticles / Q000737:chemistry*; D008856:Microscopy, Fluorescence / Q000379:methods*; D015336:Molecular Probe Techniques; D009374:Neoplasms, Experimental / Q000276:immunology / Q000473:pathology*; D013059:Spectrum Analysis, Raman / Q000379:methods*
D000906:Antibodies; D000951:Antigens, Neoplasm; D015815:Cell Adhesion Molecules; D000071858:Epithelial Cell Adhesion Molecule; D006046:Gold