Rapid and sensitive phenotypic marker detection on breast cancer cells using surface-enhanced Raman scattering (SERS) imaging

We report a surface-enhanced Raman scattering (SERS)-based cellular imaging technique to detect and quantify breast cancer phenotypic markers expressed on cell surfaces. This technique involves the synthesis of SERS nano tags consisting of silica-encapsulated hollow gold nanospheres (SEHGNs) conjugated with specific antibodies. Hollow gold nanospheres (HGNs) enhance SERS signal intensity of individual particles by localizing surface electromagnetic fields through pinholes in the hollow particle structures. This capacity to enhance imaging at the level of single molecules permits the use of HGNs to detect specific biological markers expressed in living cancer cells. In addition, silica encapsulation greatly enhances the stability of nanoparticles. Here we applied a SERS-based imaging technique using SEHGNs in the multiplex imaging of three breast cancer cell phenotypes. Expression of epidermal growth factor (EGF), ErbB2, and insulin-like growth factor-1 (IGF-1) receptors were assessed in the MDA-MB-468, KPL4 and SK-BR-3 human breast cancer cell lines. SERS imaging technology described here can be used to test the phenotype of a cancer cell and quantify proteins expressed on the cell surface simultaneously. Based on results, this technique may enable an earlier diagnosis of breast cancer than is currently possible and offer guidance in treatment. (C) 2013 Elsevier B.V. All rights reserved.The National Research Foundation of Korea supported this work through grant numbers R11-2008-0061852 and K20904000004-12A0500-00410. The Nano Material Technology Development Program also supported this work, through the National Research Foundation of Korea, funded by the Ministry of Education, Science, and Technology (grant number 2012035286). This research was also partially supported by the Agency for Defense Development through Chemical and Biological Defense Research Center. SL thanks for the financial support from the National Research Foundation of Korea (grant number 2012R1A1A2042550)