Fluorescence properties of 3-amino phenylboronic acid and its interaction with glucose and ZnS:Cu quantum dots.

Preliminary results of a study of the interaction between 3-amino phenylboronic acid and glucose or ZnS:Cu quantum dots are presented in this paper. ZnS:Cu quantum dots with mercaptopropionic acid as a capping agent were obtained and characterized. Quenching of 3-amino phenylboronic acid fluorescence was studied by steady-state and timeresolved measurements.

Quantum dots as a possible oxygen sensor.

Results of studies on optical properties of low toxicity quantum dots (QDs) obtained from copper doped zinc sulfate are discussed in the paper. The effect of copper admixture concentration and solution pH on the fluorescence emission intensity of QDs was investigated. Quenching of QDs fluorescence by oxygen was reported and removal of the oxygen from the environment by two methods was described.

Thermostability of glucose oxidase in silica gel obtained by sol-gel method and in solution studied by fluorimetric method.

The thermostability of glucose oxidase entrapped in silica gel obtained by sol-gel method was studied by thermostimulated fluorescence of FAD at pH 5 and 7 and compared with that of the native enzyme in the solution and at the presence of ethanol. The unfolding temperatures were found to be lower for the enzyme immobilised in gel as compared with the native enzyme but higher as for the enzyme at the presence of ethanol. In gel, the thermal denaturation of glucose oxidase is independent on pH while in solution the enzyme is more stable at pH 5.

Stability of pyrene-1-carboxylic acid and other pyrene derivatives immobilized on silane gels.

The main aim of this research was to select a silane gel with appropriate composition containing fluorophore immobilized in it, in view of application of this carrier in the construction of a fluorescence optical sensor. Results of stationary fluorescence studies on gelation of silane gel with different composition, obtained as a result of acidic or basic hydrolysis using the fluorophores: pyrene-1-carboxylic acid and 1,3-bis(1-pyrenyl)propane, are presented. The form of probe during sol-gel transition and in the formed gel is discussed.

The styrylpyridine dye for the silane sol-gel transition studies by time-dependent fluorescence.

A trans-4-(p-N,N-dimethylaminostyryl)-N-vinylbenzylpyridinium chloride (vbDMASP) fluorescence probe was optimized in ground and excited state as a function of change in the microenvironment polarity, using the Amsol HyperChem program package. In the calculations, protic and aprotic solvents were used. On this basis a change in the molecule geometry after excitation, depending on the surrounding solvent, was determined.

The fluorescence studies of the sol-gel transition by styrylpyridine derivative.

The gelation process of tetraethylorthosilanes in acid environment was monitored with the trans-4-(p-N,N-dimethylaminostyryl)-N-vinylbenzylopyridinium chloride (vbDMASP) fluorescent probe. The fluorescence steady-state and anisotropy measurements of material during sol-gel transition are reported. The results are compared with fluorescence studies of the probe in a modeled viscous system of water-glycerol mixtures.