Assaying the expression of cell surface proteins has widespread application for characterizing cell type, developmental stage, and monitoring disease transformation. We report on the use of narrow band width surface-enhanced Raman scattering (SERS) nanoparticles as optical labels for multiplexed immunophenotying.  Two types of surface coatings were investigated to passivate the gold nanoparticles, incorporate SERS functionality, and to facilitate attachment of targeting antibodies. Thiolated poly(ethylene glycol) forms dative bonds with the gold surface and is compatible with multiple physisorbed Raman-active reporter molecules. Ternary lipid bilayers are used to encapsulate the gold nanoparticles particles, and incorporate three different classes of Raman reporters. TEM, UV-Visible absorbance spectroscopy, DLS, and electrophoretic light scattering were used characterize the particle coating. Colourimetric protein assay, and secondary antibody labelling were used to quantify the antibody conjugation.<br/>        Three different <i>in vitro </i>models were used to investigate the binding efficacy and specificity of SERS labels for their biomarker targets. Primary human CLL cells, LY10 B lymphoma, andA549 adenocarcinoma lines were targeted. Dark field imaging was used to visualize the colocalization of SERS labels with cells, and evidence of receptor clustering was obtained based on colour shifts of the particles’ Rayleigh scattering. Widefield, and spatially-resolved Raman spectra were used to detect labels singly, and in combination from labelled cells. Fluorescence flow cytometry was used to test the particles’ binding specificity, and SERS from labelled cells was also detected using a modified flow cytometer. The work reported herein demonstrates SERS immunophenotyping using multiple cancer models, and adaptability to clinical instrumentation.<br/>

Surface-enhanced Raman scattering nanoparticles as optical labels for imaging cell surface proteins

249th National Meeting (2015)

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