A fluorescent compound 3,4-bis(2,4-difluorophenyl)-maleimide from the 3,4-diaryl-substituted maleimides was synthesized and determined to have a Stokes shift of 140 nm (λ(abs) 341 nm, λ(em) 481 nm), a high fluorescent quantum yield (Φ(fl) 0.61) and an extinction coefficient ε((340)) of 48 400 M(-1) cm(-1) in dichloromethane. For the first time we demonstrated the successful implementation of a...

In two-color fluorescence correlation spectroscopy (TCFCS), the fluorescence intensities of two fluorescently-labeled species are cross-correlated over time and can be used to identify static and dynamic interactions. Generally, fluorophore labels are chosen that do not undergo Förster resonance energy transfer (FRET). Here, a general TCFCS theory is presented that accounts for the possibility ...

We study targeted energy transfer (TET) mechanisms by applying a nonlinear energy sink (NES) to suppress regenerative instabilities in a 2-DOF planar machine tool model. With the help of a numerical continuation tool, DDEBIFTOOL, we show that the tool instability is generated through a subcritical Hopf bifurcation in this simplified tool model. Studying modal energy exchanges reveals that only ...

Red-luminescent 200 nm silica nanoparticles have been designed and prepared as a versatile platform for developing FRET (Förster resonance energy transfer) biomimetic assays. Ru(phen)₃²⁺ dye molecules embedded off-center in the silica core provide the long-lived donor emission, and a near-infrared labeled analyte serves as fluorescent acceptor (the measured R₀ of this D-A pair is 4.3 nm). A thi...

A fluorescence method for the detection of DNA methylation and the assay of methyltransferase activity is proposed using gold nanorods as a fluorescence quencher on the basis of fluorescence resonance energy transfer. It is demonstrated that this method is capable of detecting methyltransferase with a detection limit of 0.25 U mL(-1), which might make this method a good candidate for monitoring...

The analysis of single-molecule fluorescence resonance energy transfer (FRET) trajectories has become one of significant biophysical interest. In deducing the transition rates between various states of a system for time-binned data, researchers have relied on simple, but often arbitrary methods of extracting rates from FRET trajectories. Although these methods have proven satisfactory in cases ...

Genetically-encoded biosensors based on FRET between fluorescent proteins of different hues enable quantitative measurement of intracellular enzyme activities and small molecule concentrations. (To listen to a podcast about this feature, please go to the Analytical Chemistry website at pubs.acs.org/journal/ancham.).

We present the first demonstration that fluorescence resonance energy transfer can be used to track the motion of a single molecule undergoing conformational changes. As a model system, the conformational changes of individual three-helix junction RNA molecules induced by the binding of ribosomal protein S15 or Mg(2+) ions were studied by changes in single-molecule fluorescence. The transition ...

It appears that equilibrium unfolding transitions of many small proteins can be described as two-state transitions, because the probes commonly used to measure such transitions cannot detect the underlying heterogeneity inherent in protein folding and unfolding reactions. Time-resolved fluorescence or Forster resonance energy transfer (TRFRET) measurements have the potential to uncover such het...