中文摘要：

利用＂适配体-目标分子-适配体＂的＂三明治＂夹心方式构建液晶生物传感检测三磷酸腺苷（ATP）.将ATP核酸适配体片段作为捕获探针固定在经TEA/DMOAP混合组装膜修饰的玻片基底表面,当ATP存在时,裂开的两部分核酸适配体与ATP结合形成双链结构,有效诱导液晶分子取向发生变化从而引起光学信号的亮度及颜色发生变化,实现对ATP的检测,该方法在ATP浓度为10 nmol/L时仍可观测到明显的光学信号变化.这种＂适配体-目标分子-适配体＂的＂三明治＂夹心式液晶生物传感方法具有无需标记,操作简单等特点,在快速检测小分子等物质领域中有广泛的应用前景.

英文摘要：

A novel liquid crystal（LC） biosensor based on the recombination of split aptamer chip was developed for the detection of adenosine triphosphate（ATP）.One glass slide of the LC cell is first modified with the TEA/DMOAP mixed self-assembled monolayer（SAM） to ensure the homeotropic alignment of LC molecules and the black background of LC cell optical image under the crossed polarized light.The single-strand ATP aptamer is split into two fragments in this method.One of which,as capture probe,is covalently immobilized on the SAM,while another is used as the detection probe.In the presence of ATP,those two fragments will be combined with each other and exhibit the same role as the ATP aptamer.This binding event leads to a great enhancement in the optical signal of the LC biosensor due to the space size from small to big,which can effectively disrupt the orientational arrangement of LCs,resulting in the corresponding changes of optical images under the crossed polarized light.But in the absence of ATP,those two fragments can not be combined with each other,and as a result,there is no orientational response of LCs and the optical image under the crossed polarized light is still black.So the LC-based imaging method has a sensitive and clear distinction between positive and negative results.On the basis of such an inhibition mechanism the LC biosensor can be used as an effective way to realize the detection of ATP.When the concentration of analyte ATP below a critical value（10 nmol/L）,there is no clear change in the optical image.The results showed that the detection limit of ATP is 10 nmol/L.This study provides a simple and sensitive ATP LC biosensing approach and offers effective strategies for the development of small molecules LC biosensors.