Fluorescence correlation spectroscopy using quantum dots: advances, challenges and opportunities.

Semiconductor nanocrystals (quantum dots) have been increasingly employed in measuring the dynamic behavior of biomacromolecules using fluorescence correlation spectroscopy. This poses a challenge, because quantum dots display their own dynamic behavior in the form of intermittent photoluminescence, also known as blinking. In this review, the manifestation of blinking in correlation spectroscopy will be explored, preceded by an examination of quantum dot blinking in general.

The Electronic Structure and Spectrum of RhC: New Bands in the 400-500 nm Region, Interacting (2)Sigma(+) and (2)Pi States, and Deperturbation.

Rhodium monocarbide (RhC) molecules were generated using a laser ablation/supersonic molecular beam source. Laser-induced and dispersed-fluorescence (DF) techniques were used to study the visible spectrum between 400 and 530 nm. Rh(12)C/Rh(13)C isotope shifts, DF, and excited level lifetime measurements assisted in classifying the observed bands into three series: the known C(2)Sigma(+) <-- X(2)Sigma(+) system (short excited state lifetimes) and the two spin subsystems of a (2)Pi(i) <-- X(2)Sigma(+) transition (long excited state lifetimes).