An excitation and emission wavelength dependent non-exponential fluorescence decay behaviour of room temperature ionic liquids (RTILs) has been noted. Average fluorescence lifetimes have been found to vary by a factor of three or more. Red emitting dyes dissolved in RTILs are found to follow hitherto unobserved single exponential fluorescence decay behaviour.

Metallic surfaces and particles can have dramatic effects on fluorescence, including localized excitation, increased quantum yields, increased photostability and increased distances for resonance energy transfer (RET), and directional emission. While all these effects have not yet been realized in a single system, metal-enhanced fluorescence promises to provide the next generation of high sensi...

BACKGROUND AND OBJECTIVE The hamster cheek pouch carcinogenesis model, using chronic treatments of dimethylbenz[alpha]anthracene (DMBA) was used as a model system to investigate changes in epithelial tissue autofluorescence throughout the dysplasia-carcinoma sequence. STUDY DESIGN/MATERIALS AND METHODS Fluorescence emission spectra were measured weekly from 42 DMBA-treated animals and 20 cont...

Excitation–emission matrix (EEM) fluorescence spectroscopy was employed to study the chemical nature of organic matter readily released into solution from sediment particles during episodes of resuspension. Surface sediment samples collected from five locations within the Hudson River Estuary and the Inner New York Bight were resuspended in their respective bottom waters for periods ranging fro...

Crystals of 1,4-bis(2-hydroxy-2-methyl-3-butynyl)-2-fluorobenzene 4 have a rich packing structure with four distinct molecules in the unit cell. A complex hydrogen bonding network results in the formation of cofacial trimers, cofacial dimers, and monomers within the same unit cell. Given a remarkable opportunity to investigate the effect of aggregation on the photophysics of 1,4-diethynylbenzen...

An ultrasound coupled handheld-probe-based optical fluorescence molecular tomography (FMT) system has been in development for the purpose of quantifying the production of Protoporphyrin IX (PPIX) in aminolevulinic acid treated (ALA), Basal Cell Carcinoma (BCC) in vivo. The design couples fiber-based spectral sampling of PPIX fluorescence emission with a high frequency ultrasound imaging system,...

PURPOSE Advances in two-photon (2P) deep tissue imaging provide powerful options for simultaneously viewing multiple fluorophores within tissues. We determined imaging parameters for optimally visualizing three fluorophores in the human trabecular meshwork (TM) to simultaneously detect broad-spectrum autofluorescence and multiple fluorophores through a limited number of emission filters. METH...

We found that the dye nile red, 9-diethylamino-5H-benzo[alpha]phenoxazine-5-one, can be applied as a fluorescent vital stain for the detection of intracellular lipid droplets by fluorescence microscopy and flow cytofluorometry (J. Cell. Biol. 1985. 100: 965-973). To understand the selectivity of the staining, we examined the fluorescence properties of nile red in the presence of organic solvent...

A laboratory class is described to introduce the biochemistry major students to the basic concepts and various applications of fluorescence spectroscopy. Through simple and inexpensive experiments the students learn how to record excitation and emission spectra and measure intrinsic protein fluorescence and its quenching to elucidate the local tryptophan environment. Free tryptophan, ovalbumin,...

Dynamic two-dimensional fluorescence correlation spectroscopy (2D FCS) is presented in the general form. Dynamic 2D FCS evaluates the time correlation function between two wavelength axes when an external perturbation is applied to the sample. It displays the vibronic features with similar time response functions in the synchronous correlation spectrum and the features with different time respo...