Experiments indicated that protein can enhance the fluorescence of the 4-chlorosulfo-(2′-hydroxylophenylazo)-rhodanine-Ti(IV) complex [ClSARP-Ti(IV)] in the presence of bis(2-ethylhexyl)sulfosuccinate sodium salt (AOT) microemulsion. Based on this, a sensitive and reproducible fluorometric method for the determination of micro amount protein was developed. The calibration curves of four proteins were given. Under the optimum experimental conditions, the enhanced fluorescence intensity of the system was in proportional to the concentration of protein in the range of 0.1–11 μg mL−1 for bovine serum albumin (BSA), 1.0–10 μg mL−1 for human serum albumin (HSA), 1.0–50 μg mL−1 for ovalbumin (Ova) and 2.5–18 μg mL−1 for γ-globulins (γ-G). Their detection limits were 0.070, 0.071, 0.33 and 0.22 μg mL−1, respectively. The ClSARP-Ti(IV) complex as a spectral probe can be used to the determination of protein in milk powder and oatmeal yielding with satisfactory results. Therefore, the proposed method is one of the most sensitive methods available. In addition, the interaction mechanism of this system is studied by multi-techniques. 相似文献
Density functional B3LYP method with 6-31++G** basis set is applied to optimize the geometries of the luteolin, water and luteolin–(H2O)n complexes. The vibrational frequencies are also studied at the same level to analyze these complexes. We obtained four steady luteolin–H2O, nine steady luteolin–(H2O)2 and ten steady luteolin–(H2O)3, respectively. Theories of atoms in molecules (AIM) and natural bond orbital (NBO) are used to investigate the hydrogen bonds involved in all the systems. The interaction energies of all the complexes corrected by basis set superposition error, are within −13.7 to −82.5 kJ/mol. The strong hydrogen bonding mainly contribute to the interaction energies, Natural bond orbital analysis is performed to reveal the origin of the interaction. All calculations also indicate that there are strong hydrogen bonding interactions in luteolin–(H2O)n complexes. The OH stretching modes of complexes are red-shifted relative to those of the monomer. 相似文献
The center of it all : An antitumor‐active trinuclear platinum complex forms unprecedented interstrand cross‐linked triadducts with 18‐mer DNA duplexes (see figure; complex in yellow with the platinum centers in red) and behaves differently from its dinuclear analogue.
