Investigating the Dynamics of Cellular Processes at the Single Molecule Level with Semiconductor Quantum Dots

Abstract

The unique optical properties of semiconductor quantum dots (QDs) make them a powerful tool for ultrasensitive biological detection. Thanks to their large extinction coefficient and photostability, QDs can be detected at the single molecule level with high signal-to-noise ratio. This enables new experiments in which individual QD-labeled biomolecules are tracked with nanometer accuracy as they move in their natural cellular habitats. The ability to observe single biomolecules is essential to account for the stochastic nature of biological processes and to obtain information that remains elusive for biochemical, genetic, and conventional imaging methods. In living cells, single QD imaging has already been used to unravel the diffusion properties of membrane receptors as well as to analyze the motion of intracellular molecular motors. When combined with new optical and biochemical techniques, QDs will contribute to advanced biological imaging at the molecular scale and allow new studies on the dynamics of cellular processes.