Quantum Optics: Colloidal Fluorescent Semiconductor Nanocrystals (Quantum Dots) in Single-Molecule Detection and Imaging

Abstract

Coming from the electronic material sciences, semiconductor nanocrystals, called quantum dots (QDs), have emerged as new powerful fluorescent probes for in vitro and in vivo biological labeling and single-molecule experiments. QDs possess several unique optical properties that make them very attractive over conventional fluorescent dyes and genetically encoded proteins technologies. They have precise emission color tunability by size due to quantum confinement effects, better photostability and brightness, wide absorption band and very narrow emission band for multiplexing, and increased fluorescence lifetimes. These characteristics, combined with some dramatic progresses achieved in surface chemistry, biocompatibility and targeting strategies have allowed their recent advances in the field of single-molecule detection and imaging

Assessing the Stochastic Intermittency of Single Quantum Dot Luminescence for Robust Quantification of Biomolecules

“…A schematic of this assembly is shown in Figure 1. Wells produced in this way have a base surface area of 38.5 mm 2 and hold approximately 100 μL, though the well volume can vary as the thickness is determined when the PDMS layer is cast.…”

“…This paper presents a methodology for digital quantification of biomolecules by detecting signal variations from single quantum dot (QD) reporters. QDs are highly fluorescent semiconductor nanocrystals that are widely used as labels for various biological and chemical applications. − Our method takes advantage of the stochastic blinking process intrinsic of QDs to measure the signal variation and compare it to variations of the background. Current detection techniques have achieved the ability to detect a single molecule; however, in order to quantify single molecules, the development of methodologies that enable high efficiency detection of individual molecules is crucial.…”