Evdokimov Iu M, Shtykova E V, Salianov V I, Skuridin S G
Biofizika. 2013 Mar-Apr;58(2):210-20.
The effects of small size (approximately 2 nm) gold nanoparticles on the properties of particles of cholesteric liquid-crystalline dispersions formed by double-stranded DNA molecules were analyzed. It has been shown that gold nanoparticles induce two different processes. First, they facilitate reorganization of the spatial cholesteric structure of dispersion particles to nematic one. This process is accompanied by the fast decrease in the amplitude of abnormal band in the CD spectrum. Second, they can form ensembles consisting of gold nanoparticles. This process is accompanied by the development and displacement of surface plasmon resonance band in the visible region of the absorption spectrum. The appearance of this band is analyzed by considering two different models of the formation of ensembles consisting of gold nanoparticles. By small-angle X-ray scattering we performed structural analysis of phases formed by DNA cholesteric liquid-crystalline dispersion particles treated with gold nanoparticles. As a result of this study it was possible to prove the formation of linear clusters of gold nanoparticles in the "free space" between the adjacent DNA molecules fixed in the quasinematic layers of liquid-crystalline particles. It has been hypothesized that the formation of linear clusters of gold nanoparticles is most likely related to DNA molecules, ordered in the spatial structure of quasinematic layers, and the toxicity of these nanoparticles in biological systems hypothesized.
分析了小尺寸（约2纳米）金纳米颗粒对由双链DNA分子形成的胆甾相液晶分散体颗粒性质的影响。结果表明，金纳米颗粒引发了两种不同的过程。首先，它们促进分散体颗粒的空间胆甾相结构重排为向列相结构。这一过程伴随着圆二色光谱中异常带振幅的快速下降。其次，它们能形成由金纳米颗粒组成的聚集体。这一过程伴随着吸收光谱可见光区域表面等离子体共振带的出现和位移。通过考虑由金纳米颗粒组成的聚集体形成的两种不同模型来分析该带的出现。通过小角X射线散射，我们对用金纳米颗粒处理的DNA胆甾相液晶分散体颗粒形成的相进行了结构分析。这项研究的结果证明了在固定于液晶颗粒准向列层中的相邻DNA分子之间的“自由空间”中形成了金纳米颗粒的线性簇。据推测，金纳米颗粒线性簇的形成很可能与在准向列层空间结构中有序排列的DNA分子有关，并推测了这些纳米颗粒在生物系统中的毒性。
