Selective detection of cancer using spectroscopic photoacoustic imaging and bioconjugated gold nanoparticles

Highly proliferative cancer cells over express molecular markers such as epidermal growth factor receptor (EGFR). When specifically targeted gold nanoparticles bind to EGFR they tend to cluster on the cell membrane leading to an optical red-shift in the plasmon resonance frequency and an increase in absorption in the red region. These changes in optical properties provide the opportunity for photoacoustic imaging to differentiate cancer cells from surrounding benign cells - the contrast in photoacoustic imaging is based on the optical absorption properties. The imaging experiments were performed using ex-vivo tumor models. The results of our study indicate that photoacoustic imaging is capable of highly sensitive and selective detection of cancer cells by utilizing the plasmon resonance coupling effect of EGFR targeted gold nanoparticles.