Nano-materials On The Thiophene Thiazide Drugs And Dna Interactions Affect

1. Interaction of thionin and anionic surfactant SDSUV-vis Spectroscopy and fluorescence spectroscopy were employed to investigate the interaction of thionin and anionic surfactant SDS. Furthermore, the effects of the other anionic surfactants with different chain length and different hydrophile groups were cpmpaired. The results indicated that when the concentration of SDS is lower than 8.0×10-3 mol/L, the transformation of thionin monomer into H?type dimer forms increase as the concentration increases. However, the anionic surfactants with longer chain or the plane rigidity ring, facitate the transformation of thionin monomer into H?type dimer forms. When the concentration of SDS is larger than 8.0×10-3 mol/L, H?type dimer forms transform into thionin monomer. The results of fluorescence pola- rization measurements and 1H NMR indicated that when the concentration of SDS was relatively low, thionine was combined with SDS monomer through the hydrophobic binding, and thionine can be partly solublized in the SDS micelles. The study of isothermal titration microcalorimetry (ITC) indicated that when the concentration of SDS is below 8.0×10-3 mol/L, the system is exothermic reaction due to the hydrophobic interaction; when the concentration of SDS is above 8.0×10-3 mol/L, the system is endothermic reaction due to dissocation of SDS micelles; and when the concentration of SDS is in excess of cmc, the interaction of SDS with thionine is saturated.2. The influence of thionine and DNA in presence of SDS micellesThe effect of anionic surfactant SDS on the interaction of thionine with DNA was investigatged by UV-vis spectroscopy and fluorescence spectroscopy. The results show that SDS can make the thionine combined with DNA transform monomer into H?type dimer forms increase as increasing of the concentration of SDS. It is shown that the interaction of thionine and SDS is stronger than that of thionine and DNA. The result indicated that diffusion movement increases untill equilibrium with the increasing concentration of SDS by fluorescence polarization measurement, implying that thionine waslocated in a more compacted environment, which confirms the above spectral explaination. CD results indicate that DNA transforms from B form to A form with SDS added. This suggests that there exists hydrophobic interaction between the hydrophobic chains of SDS and the bases of DNA, which implies in the alteration of the double helix structure of DNA.3. Adsorption of thionin on the different sizes of gold nanoparticlesThe adsorption behavior of thionine on gold nanoparticles of two different mean diameters, 18 and 5 nm, was compared by using UV–vis spectroscopy, fluorescence spectroscopy, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS). It is found that the addition of small particles makes the monomer peak of thionine finally disappear, and the corresponding dimer peak is significantly increased. Small gold nanoparticles make the equilibrium between the monomer and H?type dimer forms of thionine move largely toward the dimer forms. Due to the stronger binding between thionine and small gold nanoparticles, the fluorescence quenching of thionine by small particles is enhanced compared to large particles, and the quenching is both static and dynamic. TEM images indicate that the addition of thionine results in a heavy clustering for small particles, and the resulting thionine–gold nanoclusters of about 45 nm were obtained. For 18 and 5 nm particles, the surface-to-volume atomic ratios are about 0.0597 and 0.2148, respectively. The higher surface-to-volume atomic ratio and the higher surface free energy result in stronger binding of thionine on small particle surfaces, which can be used to modulate the arrangement of dye molecules on particle surfaces, and thus control the properties of organic–inorganic nanocomposite materials. 4. Control of the interaction of DNA with methylene blue by gold nanoparticles.The interaction model between methylene blue and DNA was investigated by UV-vis, fluorescence spectroscopy and fluorescence polarization measurement. It is found that the interaction may be related to the molar ratio of DNA and methylene blue. When the molar ratio of DNA to MB is relatively low, the intercalation is dominant; when the molar ratio is increased to a certain concentration, the interaction between MB and DNA is mainly electrostatic. The addition of gold nanoparticles into MB?DNA system weakens the intercalation and the electrostatic interaction. DLS and TEM results indicate that addition of gold nanoparticles causes the formation of more compacted MB?DNA complexes, which is accompanied with the displacement of MB from DNA. During the binding process, gold nanoparticles makes the DNA transform B form to A form. Therefore, the interaction made of MB with DNA can be adjusted by using gold nanoparticles.