State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
Biosens Bioelectron. 2014 Dec 15;62:84-9. doi: 10.1016/j.bios.2014.06.029. Epub 2014 Jun 20.
A novel highly-sensitive liquid crystal (LC) biosensing approach based on target-triggering DNA dendrimers was developed for the detection of p53 mutation gene segment at the LC-aqueous interface. In this study, the mutant-type p53 gene segment was the target to trigger the formation of DNA dendrimers from hairpin DNA probes by hybridization chain reaction, and the latter as a 'signal enhancement element' further induced the LC reorientation from tilted to homeotropic alignment, resulting in a corresponding optical changes of LC biosensors from birefringent to honeycombed textures or dark framework. The distinct optical reorientational appearances can serve as a characteristic signal to distinguish target concentrations ranging from 0.08 nM to 8 nM. Moreover, these optical phenomena suggest that the LC reorientation is related to the electric-dipole coupling between the adsorbed DNA and LC molecules, the conformational constraints of DNA and the internal electric field induction upon hybridization. This label-free LC biosensing strategy can open up a new platform for the sensitive detection of specific DNA sequences and enrich the application scope of an LC biosensing technique.
一种新型的基于靶标触发 DNA 树状大分子的高灵敏度液晶（LC）生物传感方法，用于在 LC-水界面检测 p53 突变基因片段。在本研究中，突变型 p53 基因片段是触发发夹 DNA 探针通过杂交链式反应形成 DNA 树状大分子的靶标，后者作为“信号增强元件”进一步诱导 LC 从倾斜排列到各向同性排列的重取向，从而导致 LC 生物传感器的相应光学变化从双折射到蜂窝状纹理或暗框架。独特的光学重取向外观可用作特征信号，以区分浓度范围为 0.08 nM 至 8 nM 的靶标。此外，这些光学现象表明 LC 重取向与吸附 DNA 和 LC 分子之间的电偶极耦合、DNA 的构象约束以及杂交时的内部电场感应有关。这种无标记的 LC 生物传感策略可为特定 DNA 序列的灵敏检测开辟新平台，并丰富 LC 生物传感技术的应用范围。
