The paper describes the use of the Polilight, a light source based on a xenon arc lamp, to exploit the fluorescence properties of semen as an aid to searching fabrics for stains in sexual assault cases. The broad excitation spectrum of semen allows the fluorescence to be generated at a range of wavelengths. This permits the excitation and emission conditions to be selected that minimize interfe...

This review covers the field of excited electronic-state chemical reactions in small clusters. The clusters emphasized are those comprised of an organic chromophore that is electronically excited to initiate the reaction and of various coreactant molecules ranging from water and ammonia to ethers, amines, aromatics, alkanes, alkenes, and diatomics. The reactions discussed include vibrational re...

We investigate the coupling of a single molecule to a single spherical gold nanoparticle acting as a nanoantenna. Using scanning probe technology, we position the particle in front of the molecule with nanometer accuracy and measure a strong enhancement of more than 20 times in the fluorescence intensity simultaneous to a 20-fold shortening of the excited state lifetime. Comparisons with three-...

We report here the striking anisotropy of fluorescence exhibited by crystals of native green fluorescence protein (GFP). The crystals were generated by water dialysis of highly purified GFP obtained from the jellyfish Aequorea. We find that the fluorescence becomes six times brighter when the excitation, or emission, beam is polarized parallel (compared with perpendicular) to the crystal long a...

Fluorescence spectroscopy is a promising technology for detection of epithelial precancers and cancers. While age and menopausal status influence measurements in the cervix, other variables do not significantly affect the diagnosis. In this study we examine probe pressure as a variable. A fiber optic probe to measure fluorescence spectra at different calibrated levels of pressure was designed a...

Accurate quantification of photosensitizers is in many cases a critical issue in photodynamic therapy. As a noninvasive and sensitive tool, fluorescence imaging has attracted particular interest for quantification in pre-clinical research. However, due to the absorption of excitation and emission light by turbid media, such as biological tissue, the detected fluorescence signal does not have a ...

Two-photon (2P) excitation of the second singlet (S₂) state was studied to achieve deep optical microscopic imaging in brain tissue when both the excitation (800 nm) and emission (685 nm) wavelengths lie in the "tissue optical window" (650 to 950 nm). S₂ state technique was used to investigate chlorophyll α (Chl α) fluorescence inside a spinach leaf under a thick layer of freshly sliced rat bra...

We developed a new class of two-photon excitation-stimulated emission depletion (2PE-STED) optical microscope. In this work, we show the opportunity to perform superresolved fluorescence imaging, exciting and stimulating the emission of a fluorophore by means of a single wavelength. We show that a widely used red-emitting fluorophore, ATTO647N, can be two-photon excited at a wavelength allowing...

The nonradiative decay processes of BODIPYs can be considerably prevented by complexation with CB[7] to making utmost absorbed excitation energy used for high emission which plays a crucial role in fluorescence labelling and optoelectronic devices.

Fluorophores from the hemolymph of yellow sac spiders (Cheiracanthium mildei) have been characterized using excitation emission matrix (EEM) fluorescence spectroscopy. This approach provides characterization of fluorophores present in the organism without having to isolate pure samples. Minimal variation occurs between individual samples and each EEM has two distinct peaks, suggesting two fluor...