Abstract

Lung cancer is the leading cause of cancer related mortalities. With current imaging modalities, non-invasive diagnosis of this deadly cancer is difficult due to the lack in specificity. Photonics based optical molecular imaging is a promising alternative for early lung cancer diagnosis because of its molecular based detection for specificity and relatively low cost instrumentation. In particular, gold nanoparticle-based surface enhanced Raman scattering (SERS) probes have shown great promise for disease detection and diagnosis because of its remarkable sensitivity and its ease of engineering for high specificity. Here, a stabilized, biocompatible SERS probe, Raman active phospholipid gold nanoparticles, is synthesized and conjugated to epidermal growth factor to target its receptor, epidermal growth factor receptor (EGFR), a common lung cancer biomarker. This novel nanoparticle encapsulates Raman molecules adsorbed on 60 nm colloidal gold with a phospholipid bilayer coating which show structural and functional stability in serum over 24 hours. Moreover, when conjugated with epidermal growth factor, it specifically detects and localizes EGFR on lung carcinoma cells. We used transmission electron microscopy, Raman and UV spectroscopy to validate the novel nanoparticle’s reproducibility and stability. We also validated its molecular specificity and use it as an efficient contrast agent with in vitro confocal reflectance microscopy on lung carcinoma. This novel lipid-based SERS probe provides a viable alternative as a tool for detecting lung cancer biomarkers for non invasive, ultrasensitive and specific diagnoses.

© 2011 OSA/SPIE