In conventional microscopes, fluorescence emission is separated from the backscattered illumination using the Stokes shift, whereby the emission occurs at a longer wavelength to the excitation. Such separation is usually achieved through a combination of wavelength filters that divide the spectrum into mutually exclusive excitation and emission bands. It is therefore impossible in these microsc...

The spatial and temporal coherence of the fluorescence emission controlled by a quasi-two-dimensional hybrid photonic-plasmonic crystal structure covered with a thin fluorescent-molecular-doped dielectric film is investigated experimentally. A simple theoretical model to describe how a confined quasi-two-dimensional optical mode may induce coherent fluorescence emission is also presented. Conce...

This study describes a scanning time-resolved fluorescence spectroscopy (TRFS) system designed to continuously acquire fluorescence emission and to reconstruct fluorescence lifetime images (FLIM) from a luminal surface by using a catheter-based optical probe with rotary joint and pull-back device. The ability of the system to temporally and spectrally resolve the fluorescence emission from tiss...

Dipicolinic acid (DPA) and the Ca2+ complex of DPA (CaDPA) are major chemical components of bacterial spores. With fluorescence being considered for the detection and identification of spores, it is important to understand the optical properties of the major components of the spores. We report in some detail on the room-temperature fluorescence excitation and emission spectra of DPA and its cal...

The fluorescence spectroscopy of 7-azaindole (In) incorporated in DNA oligonucleotides is investigated. Incorporation of In into DNA oligonucleotides is accomplished through standard solid-phase phosphoramidite chemistry. Fluorescence emission of the In chromophore shifts slightly to the red (from 386 nm to 388 nm) upon glycosylation at the N−1 position, but its relative fluorescence quantum yi...

1.1 Fluorescence phenomenon The absorption and subsequent emission of light by organic and inorganic specimens is typically the result of physical phenomena known as luminescence, which occurs at electronically excited states. Luminescence is formally divided into two categories: fluorescence and phosphorescence, depending on the nature of the excited state. Fluorescence occurs when a photon ex...

Chlorophyll fluorescence (Chf) emission allows estimating the photosynthetic activity of vegetation -a key parameter for the carbon cycle modelsin a quite direct way. However, measuring Chf is difficult because it represents a small fraction of the radiance to be measured by the sensor. This paper analyzes the relationship between the solar induced Chf emission and the photosynthetically active...

.a simple spectrofluorimetric method is described for the determination of doxorubicin (dxr) based on its quenching effect on the fluorescence intensity of tb 3+ - deferasirox (dfx) complex as a fluorescent probe. the excitation and emission wavelengths were 328 and 545 nm, respectively. the effects of ph, time, order of addition of reagents, concentrations of tb 3+ and dfx and the buffer volum...

In this letter, we report the first observation of metal-enhanced exciplex fluorescence, observed from anthracene in the presence of diethylaniline. Anthracene in the presence of diethylaniline in close proximity to Silver Island Films (SIFs) shows enhanced monomer and exciplex emission as compared to a non-silvered control sample containing no silver nanoparticles. Our findings suggest two com...

The scales covering the elytra of the male Hoplia coerulea beetle contain fluorophores embedded within a porous photonic structure. The photonic structure controls both insect colour (reflected light) and fluorescence emission. Herein, the effects of water-induced changes on the fluorescence emission from the beetle were investigated. The fluorescence emission peak wavelength was observed to bl...