检测神经毒气的液晶型化学传感器  

Using Liquid Crystal Sensors to Detect Organophosphonates

作　　者：张婷婷[1] 王诗鸣[1] 陈镇[1] 李广[1] 熊兴良[1] 

机构地区：[1]重庆医科大学生物医学工程研究室,重庆400016

出　　处：《传感技术学报》2014年第8期1009-1012,共4页Chinese Journal of Sensors and Actuators

基　　金：国家自然科学基金项目(30500125)

摘　　要：向列型液晶分子具有取向序而无位置序,外界物理、化学和生物刺激非常容易引起分子取向变化,进而导致偏光图像的变化。本文利用玻璃基底表面沉积的Cu2+使4-腈基-4'-戊基联苯液晶(5CB)分子获得沿面垂直取向。当有机磷存在时,有机磷与5CB竞争Cu2+结合位点,从而使5CB分子被有机磷置换而呈水平或倾斜取向。这一取向的变化在偏光条件下通过肉眼即可观察到。利用该原理制作的液晶化学传感器能检测10 ppb的二异丙基磷酸甲基酯(DIMP),响应时间仅25 s。传感器对水蒸汽、乙醇以及丙酮均不响应,具有很高的特异性。与传统方法相比,该方法具有快速、灵敏、制作简单以及不需要复杂装置等优点。The molecules in nematic liquid crystal （ LC ） phases possess long-range orientational order but no positional order.The orientation of molecules can be changed easily when exposure to different physical,chemical or biological environment.In this paper,we report that the uniform perpendicular orientation of thin films（~25μm）of the nematic liquid crystal,4-biphenyl-4′-Pentyl-carbonitrile（5CB）,supported on glass substrate with copper ions deposited on them.The orientation of the 5CB is driven from homeotropic to homogeneous by the competitive binding of the nitrile groups of 5CB and DIMP for the surface-immobilized copper ions in the presence of organophosphonate compounds in gas phases.This orientational transition of the LC can be observed with the naked eye by using a pair of polarizer.The Sensor can respond to 10 ppb of DIMP and the response time is approximately 25 s.The system is also demonstrated to exhibit specificity.The Sensor does not respond to gaseous streams containing ethanol,acetone and water,respectively.This system does not require complex instrumentation and could provide rapid,sensitive and simple method to detect Organophosphonates compare to traditional methods.

关 键 词：液晶 传感器 取向 

分 类 号：O659.21[理学—分析化学]