Christina M Maclaughlin

Publications (3)13.81 Total impact

• Article: Surface-Enhanced Raman Scattering Dye-Labeled Au Nanoparticles for Triplexed Detection of Leukemia and Lymphoma Cells and SERS Flow Cytometry.

  Christina M Maclaughlin, Nisa Mullaithilaga, Guisheng Yang, Shell Y Ip, Chen Wang, Gilbert C Walker
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  ABSTRACT: The labeling of cell surface receptors by fluorescent markers is an established method for the identification of cell phenotype in both research and clinical settings. Fluorescence dye labeling has inherent constraints, most notably the upper limit of labels per cell that may be probed using a single excitation source, in addition to a physical limit to the number of broad emission spectra that can be distinctly collected within the visible wavelength region. SERS labeling has the potential to mitigate these shortfalls. Herein, antibody-targeted, PEG-coated surface-enhanced Raman scattering (SERS) Au nanoparticles are used simultaneously to label three cell surface markers of interest on malignant B cells from the LY10 lymphoma cell line. The SERS probes were characterized by multiple methods to confirm their monodispersity and functionalization with both PEG and monoclonal antibodies. The specificity of the particles' cell labeling was demonstrated on both primary chronic lymphocytic leukemia and LY10 cells using SERS from cell suspensions and confocal Raman mapping, respectively. Fluorescence flow cytometry was employed to confirm the binding of SERS probes to LY10 over large cell populations, and the particles' SERS was collected directly from labeled cells using a commercial flow cytometer. To the best of our knowledge, this is the first demonstration of SERS flow cytometry from cells tagged with targeted SERS probes.
  Langmuir 01/2013; · 4.19 Impact Factor
• Article: Evaluation of SERS labeling of CD20 on CLL cells using optical microscopy and fluorescence flow cytometry.

  Christina M Maclaughlin, Edward P K Parker, Gilbert C Walker, Chen Wang
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  ABSTRACT: Immunophenotyping of lymphoproliferative disorders depends on the effective measurement of cell surface markers. The inherent light-scattering properties of plasmonic nanoparticles (NPs) combined with recent developments in NP design may confer significant advantages over traditional fluorescence probes. We report and evaluate the use of surface-enhanced Raman scattering (SERS) gold NPs (AuNPs) conjugated to therapeutic rituximab antibodies for selective targeting of CD20 molecules. SERS AuNPs were prepared by adsorbing a Raman-active dye onto the surface of 60 nm spherical AuNPs, coating the particles with 5 kDa polyethylene glycol, and conjugating rituximab to functional groups on polyethylene glycol. The effective targeting of CD20 on chronic lymphocytic leukemia cells by rituximab-conjugated SERS AuNPs was evaluated by dark-field imaging, Raman spectroscopy, and flow cytometry with both competitive binding and fluorescence detection procedures. Evidence of CD20 clustering within approximately 100 nm was observed.
  Nanomedicine: nanotechnology, biology, and medicine 04/2012; · 5.44 Impact Factor
• Article: Phospholipid membrane encapsulation of nanoparticles for surface-enhanced Raman scattering.

  Shell Ip, Christina M MacLaughlin, Nikhil Gunari, Gilbert C Walker
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  ABSTRACT: Lipid-encapsulated surface-enhanced Raman scattering (SERS) nanoparticles, with promising applications in biomedical diagnostics, were produced. Gold nanoparticles, 60 nm in diameter, were coated with a ternary mixture of DOPC, sphingomyelin, and cholesterol. The lipid layer is versatile for engineering the chemical and optical properties of the particles. The stability of the lipid-encapsulated particles is demonstrated over a period of weeks. The versatility of the layer is demonstrated by the incorporation of three different Raman-active species using three different strategies. The lipid layer was directly observed by TEM, and the SERS spectrum of the three dye species was confirmed by Raman spectroscopy. UV-vis absorption and dynamic light scattering provide additional evidence of lipid encapsulation. The encapsulation is achieved in aqueous solution, avoiding phase transfer and possible contamination from organic solvents. Furthermore, when fluorescent dye-labeled lipids were employed in the encapsulant, the fluorescence and SERS activity of the particles were controlled by the use of dissolved ions in the preparation solution.
  Langmuir 06/2011; 27(11):7024-33. · 4.19 Impact Factor