Fluorescence quenching properties of copper(II) ions have been used for designing Cu(II) sensitive fluorescent molecular probes. In this paper, we demonstrate that static quenching plays a key role in free Cu(II)-mediated fluorescence quenching of a near infrared (NIR) fluorescent dye cypate. The Stern-Volmer quenching constant was calculated to be KSV = 970,000 M in 25 mM MES buffer, pH 6.5 at...

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...

The surface parameter of nanoparticles such as hydrophobicity and a hydrophilicity on protein structure and function is very important. In this study, conformational changes of glucose oxidase (GOx) in the mercaptopurine: GNPs and 11-mercaptoundecanoic acid: GNPs as a hydrophobic and a hydrophilic GNPs surface was investigated by various spectroscopic techniques, including: UV-Vis absorption, f...

the effect of external magnetic and electric fields, in the range of electroporation and magnetoporation, on lucifer yellow (ly) fluorescence in the absence of cells is studied. electric-field-induced quenching and magnetic field-induced increase are observed for fluorescence intensity of ly. regard to the fact that the variation of field-induced fluorescence, even in the absence of cells, can ...

The surface parameter of nanoparticles such as hydrophobicity and a hydrophilicity on protein structure and function is very important. In this study, conformational changes of glucose oxidase (GOx) in the mercaptopurine: GNPs and 11-mercaptoundecanoic acid: GNPs as a hydrophobic and a hydrophilic GNPs surface was investigated by various spectroscopic techniques, including: UV-Vis absorption, f...

Lichens, a symbiotic relationship between a fungus (mycobiont) and a photosynthetic green algae or cyanobacteria (photobiont), belong to an elite group of survivalist organisms termed resurrection species. When lichens are desiccated, they are photosynthetically inactive, but upon rehydration they can perform photosynthesis within seconds. Desiccation is correlated with both a loss of variable ...

Abstract. Some kinds of checking methods and principle of dissolved oxygen in water were summarized. Such as: iodometric method, current determination method (Clark dissolved oxygen electrode), conductance measurement and fluorescence quenching. The advantages and disadvantages of each method were compared, and fluorescence quenching was discussed.The method uses Ruthenium complex as fluoresce...

Fluorescence quenching of 22 polycyclic aromatic hydrocarbons by nitromethane in toluene and acetonitrile solutions has been studied. Contrary to Sawicki's observations that the fluorescence of hydrocarbons with the fluoranthene skeleton is not quenched that of 11J2and 3.4-benzofluoranthene and fluoranthene itself is quenched. These compounds have a high energy of the fluorescence transition. T...

Dithiothreitol, which completely inhibits the de-epoxidation of violaxanthin to zeaxanthin, was used to obtain evidence for a causal relationship between zeaxanthin and the dissipation of excess excitation energy in the photochemical apparatus in Spinicia oleracea L. In both leaves and chloroplasts, inhibition of zeaxanthin formation by dithiothreitol was accompanied by inhibition of a componen...

interactions of cationic tetrakis (n,n´,n´´,n´´´-tetramethyltetra-3,4-pyridinoporphyrazinatocobalt(ii) (co(tmtppa)) with synthetic polynucleotides, poly(a-t), poly(g-c) and calf thymus dna have been characterized in 5 mm phosphate buffer, ph 7.2, by optical absorption and fluorescence spectroscopy. the appearance of hypochromicity effect and the red shift in uv-vis spectrum of porphyrazine was ...