AI 中文总结
该研究发现DNA可作为高效耗尽剂，诱导DSCG液晶发生相凝聚与手性转移，还能通过诱导相转变提供检测扩增后DNA的快速光学方法。
AI 中文摘要
我们报道了作为耗尽剂的DNA存在时，色氨酸液晶色甘酸二钠（DSCG）溶液的相行为。研究表明，DNA（单链和双链均可）能诱导DSCG发生相凝聚，其体积分数比常用的类似大小的耗尽剂聚乙二醇低1000倍。通过偏振光学显微镜进行的扭转角表征显示，尽管DNA仅存在于连续相中（荧光标记DNA成像已证实），但它会在凝聚相内引入宏观手性。紫外-可见吸收光谱显示，手性的引入会大幅降低吸收系数，表明诱导的手性使DSCG聚集体的平均长度显著增加。我们还发现，扩增后事件（如PCR）典型浓度（~nmol/L）的DNA可诱导DSCG发生各向同性-双相转变，从而提供了一种快速光学方法来报告DNA的存在。总体而言，这些发现确立了DNA是一种极其高效的耗尽剂，可调节溶致液晶中的相凝聚和手性转移，从而为检测扩增后的DNA提供了一种简单的光学平台。
英文摘要
We report on the phase behavior of solutions of a chromonic liquid crystal, disodium cromoglycate (DSCG) resulting from the presence of DNA that acts as a depletant. We show that DNA (both single and double stranded) can induce phase condensation of DSCG at volume fractions a thousand-fold lower than a commonly studied depletant of similar size, namely polyethylene glycol. Twist angle characterization via polarized optical microscopy reveals DNA introduces macroscopic chirality within the condensed phase, despite being present only in the continuous phase- as confirmed by imaging of fluorescently tagged DNA. UV-vis absorption spectroscopy reveals that the introduction of chirality reduces the absorption coefficient strongly, indicating that induced chirality leads to considerable increase in the average lengths of DSCG aggregates. We also show that DNA at concentrations (~nmol/L) typical for a post amplification event (such as PCR) can induce an isotropic-biphasic phase transition of DSCG enabling a fast optical method to report the presence of DNA. Overall, these findings establish DNA as exceptionally efficient depletants that regulate both phase condensation and chirality transfer in lyotropic liquid crystals and thereby providing a simple optical platform for detection of amplified DNA.
