Aptamer-modified gold nanoparticles for targeting breast cancer cells through light scattering

In this study, we demonstrated the potential use of nucleic acid ligand (aptamers) conjugated gold nanoparticles (AuNPs) for cancer cell detection. Through specific binding of the aptamers toward platelet-derived growth factor (PDGF), MDA-MB-231 and Hs578T cells (cancer cells) that over-express PDGF, interact with Apt-AuNPs to a greater extent than do H184B5F5/M10 cells (normal cells). These results were confirmed through inductively coupled plasma mass spectrometry measurements of the gold ion concentrations within these cells. Aggregation of the Apt-AuNPs in the cytoplasm of the cancer cells led to the generation of an intense scattered light upon photo-illumination; this phenomenon allows the differentiation of cancer cells from normal cells using a dark field optical microscope. The presence of Apt-AuNPs suppressed the proliferation of MDA-MB-231 cancer cells, but not H184B5F5/M10 cells.