通过可见光谱法研究了亚甲基绿（MG）、亚甲基蓝（MB）与cT-DNA的相互作用，并且研究了纳米材料胶体金对该识别作用的影响。研究结果表明，MG、MB与DNA相互作用方式是不相同的，尽管它们在化学结构上只存在很小的差异。MG是以插入方式与DNA作用的，而MB与DNA作用存在沟槽和插入两种方式，并以沟槽方式为主。此外，通过在胶体金溶液中的研究表明，胶体金可以明显地提高小分子化合物与DNA作用检测的灵敏度。

We report a novel approach to enhance the efficient accumulation and utilization of anticancer drug daunorubicin on cancer cells through the combination with CdS nanoparticles. Our observations using confocal fluorescence scanning microscopy as well as electrochemical analysis methods demonstrate that CdS nanoparticles can readily bind with daunorubicin on the external membrane of the targeted cells and facilitate the uptake of drug molecules in the human leukemia K562 cells. Besides, our results also indicate that the competitive binding of CdS nanoparticles with accompanying anticancer drug to the membrane of leukemia K562 cells could efficiently prevent the drug release by the drug-sensitive and drug-resistant leukemia cells and thus inhibit the possible multidrug resistance of cancer cells, which could be further utilized to improve the future drug efficiency in respective tumor chemotherapies.

The binding behavior of several fluorescence dyes to calf thymus DNA has been studied by absorption, fluorescence and atomic force microscopy (AFM), which could provide direct evidence of formation modes and the corresponding nanostructural features of the ligand-DNA complexes.

Dansylamide? has been modified by the introduction of several side chains into the sulfonamide substituent. Compounds with no, or with only one positive charge at the side chains were found not to be useful for association studies with nucleotides or nucleic acids. Relatively high binding constants with moderate base selectivities have been observed with a ligand obtained from dansyl chloride and N,N9-bis(3-aminopropyl)piperazine, which contains two dansyl units and two permanently charged peralkylammonium centers. Interactions of this ligand with double-stranded nucleic acids show a biphasic binding, the first at base pair concentrations below 1027 M being only detectable by a decrease of fluorescence intensity. The second phase is characterized by increased fluorescence and by wavelength changes similar to effects observed in lipophilic solvents and by affinities of up to 5×105 M. At higher concentrations bathochromic shifts and extinction changes in UV spectra of the dye suggest an intercalation mechanism, in line with preliminary circular dichroism studies.

The effect of fl-cyclodextrin (fl-CD) on the spectral properties of quinine molecules has been specifically studied by absorption/fluorescence and Fourier transform infrared (FTIR) spectroscopy. In particular, FTIR studies of the complexation of aqueous quinine hydrochloride with fl-CD provide fresh insight into the molecular structure of the complex and reveal some important information in relation to the molecular interactions of the cyclodextrin complex system. Nuclear magnetic resonance data support the inclusion conformation of the interaction sites and the presence of hydrogen bonds which stabilize the complexes.