Quantum dots and FRET-nanobeads for probing genes, proteins, and drug targets in single cells

Quantum dots are tiny light-emitting particles on the length scale of 2-10 nm, and FRET-nanobeads for fluorophore-embedded nanoparticles on the length scale of 40-200 nm based on the phenomenon of fluorescence resonance energy transfer (FRET). These materials are emerging as a new class of biological labels with properties and applications that are not available with traditional organic dyes and fluorescent proteins. In this ASME contribution, we report new developments in using semiconductor quantum dots for quantitative imaging and spectroscopy of single cancer cells. We also show results from intracellular staining of actin filaments using FRET-nanobeads. These results raise new possibilities in disease diagnostics, drug and biochemical discovery, cancer imaging, molecular profiling, and disease staging.