ABSTRACT
In the present paper, a fluorescence method was used to study at different pH the fluorescence quenching of bovine serum albumin (BSA) by its interaction with balofloxacin (BLFX). The interaction association constants of BSA and BLFX were determined from a double reciprocal line Weaver-Burk plot. According to the Forster dipole-dipole energy transfer, the distance to be measured between the BLFX and tryptophane is 5.09 nm. From thermodynamical coordination it can be judged that the binding power between BLFX and BSA is electrostatic effect. The effect of BLFX on the conformation of BSA was also analyzed by using synchronous fluorescence spectroscopy.
Subject(s)
Fluorescence , Fluoroquinolones/chemistry , Serum Albumin, Bovine/chemistry , Animals , Cattle , Energy Transfer , Fluoroquinolones/metabolism , Kinetics , Protein Binding , Serum Albumin, Bovine/metabolism , Spectrometry, Fluorescence , Spectrophotometry, Ultraviolet , Static Electricity , ThermodynamicsABSTRACT
In this work, nano-CdS was successfully prepared. The nano-CdS was also modified with L-cysteine. Absorption and fluorescence spectra of CdS nanoparticles for different pH values, reaction times and different Cys/Cd2+/S ratios were investigated. Meanwhile a fluorescence enhancing effect was observed between trace zinc ions and the functionalized L-Cys-CdS nanoparticles. The response is linearly proportional to the concentration of zinc ions from 1.0 to 15 micromol x L(-1). The functionalized nanoparticles are hopeful of use as fluorescence probes in detecting trace elements in biological samples.
