Cancer Cells Assemble and Align Gold Nanorods Conjugated to Antibodies to Produce Highly Enhanced, Sharp, and Polarized Surface Raman Spectra:  A Potential Cancer Diagnostic Marker

• Published in: Nano letters 2007-06, Vol.7 (6), p.1591-1597
• Main Authors: Huang, Xiaohua, El-Sayed, Ivan H., Qian, Wei, El-Sayed, Mostafa A.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Carcinoma, Squamous Cell - immunology; Carcinoma, Squamous Cell - pathology; Cell Line, Tumor; Contrast Media; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General aspects, investigation technics, apparatus; Gold - chemistry; Humans; Immunoassay - methods; Materials science; Molecular Probe Techniques; Nanoscale materials and structures: fabrication and characterization; Nanotechnology - methods; Nanotubes - chemistry; Nanotubes - ultrastructure; Other topics in nanoscale materials and structures; Physics; Receptor, Epidermal Growth Factor - chemistry; Receptor, Epidermal Growth Factor - immunology; Refractometry - methods; Spectrum Analysis, Raman - methods; Tissues, organs and organisms biophysics
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl070472c

Human oral cancer cells are found to assemble and align gold nanorods conjugated to anti-epidermal growth factor receptor (anti-EGFR) antibodies. Immnoconjugated gold nanorods and nanospheres were shown previously to exhibit strong Rayleigh (Mie) scattering useful for imaging. In the present letter, molecules near the nanorods on the cancer cells are found to give a Raman spectrum that is greatly enhanced (due to the high surface plasmon field of the nanorod assembly in which their extended surface plasmon fields overlap), sharp (due to a homogeneous environment), and polarized (due to anisotropic alignments). These observed properties can be used as diagnostic signatures for cancer cells.