The use of absorption and fluorescence spectroscopy for following the progress of the photoreaction between DNA and 4-aminomethyl-4,5‘,8-trimethylpsoralen (AMT) has been investigated. Absorption at long wavelengths and fluorescence both decline upon intercalation of AMT into the DNA helix. The loss of fluorescence from AMT and the accompanying appearance of monoadduct fluorescence upon irradiat...

We report the first time-resolved fluorescence emission spectra and time-resolved fluorescence anisotropies obtained using frequency-domain fluorescence spectroscopy. We examined the fluorophore p-2-toluidinyl-6-naphthalenesulfonic acid (TNS) in viscous solvents and bound to the heme site of apomyoglobin using multifrequency phase fluorometers. Fluorescence phase shift and modulation data were ...

In This research, gold nanoparticles were synthesized and functionalized by the antibody of aflatoxins. The quenching of the fluorescence of excitation emission matrices (EEM) of two type of aflatoxins (B1, G1), provoked by the gold nanoparticles, was studied by principal component analysis (PCA) and multivariate curve resolution with alternating least squares (MCR-ALS). These aflatoxins show q...

In the context of conjugated polymers, especially those of the poly (phenylenevinylene) (PPV) family, which are promising candidates as emission material in light emitting devices such as LEDs, field effect transistors and photovoltaic devices, we have, in the present study, prepared MEH-PPV [Poly [2- methoxy-5-(2’-ethyl-hexyloxy)-1,4-phenylen-evinylene] of low molecular weight and low polydisp...

Copper oxide nanoparticles (CuO-NPs) synthesized by an implicitly environmentally benign process using Acanthospermum hispidum L. aqueous plant extract as an effective bio-oxidizing/bio-reducing agent. Phytochemical screening of the fresh aqueous leaves extract showed the presence of coumarins, tannins, saponins, phenols, flavonoids, sterols and volatile oils. Fourier transform infrared spectro...

the interaction between propranolol (prop) and human serum albumin (hsa) was studied in the presence of dimethyl methylphosphonate (dmmp). dmmp is usually considered as a simulant for chemical warfare agents (cwas). for this purpose fluorescence quenching, resonance light scattering (rls), synchronous, three-dimensional fluorescence spectroscopy and molecular dynamics (md) simulation were emplo...

Why meteorites? Meteorites and the samples returned by planetary missions supplied the extraterrestrial materials for human beings to study the solar system and beyond far away from Earth. They provide chemical and mineral compositions representing the planetary bodies in solar system, e.g., planets, satellites, asteroids, comets, and near-Earth objects. They can also serve for testing instrume...

Ultraviolet-visible (UV-vis) and fluorescence spectroscopy have been used to characterize the polyelectrolyte complexes (PECs) formed when potassium indigo tetrasulfonate (ITS) interacts with poly diallydimethylammonium chloride (PDADMAC) through columbic attraction in the presence of the reducing agent sodium bisulfite, NaHSO3. The PDADMAC facilitates both the reduction of the ITS and the stab...

We propose in this paper a biosensor scheme based on coupled plasmon-waveguide resonance (CPWR) excited fluorescence spectroscopy. A symmetrical structure that offers higher surface electric field strengths, longer surface propagation lengths and depths is developed to support guided waveguide modes for the efficient excitation of fluorescence. The optimal parameters for the sensor films are th...