原子力显微镜超微量注射检测的影响分析

Disturbance Signal in Atomic Force Microscope Based Microinjection Detection

微量注射与检测受到越来越广泛的关注和研究,例如细胞工程与基因工程中,采用显微注射其注射量对操作成功率影响巨大,注射量精确检测成为人们关注的课题。利用原子力显微镜具有纳米级高度分辨率的特点,设计悬臂装置对注射微滴重力产生的挠度进行检测,实现微滴量定量检测的目的。分析讨论影响微滴检测过程的扰动因素,其中采用悬挂机构有效抑制中高频扰动,观察注意到悬架式隔振系统水平方向的微小摆动对检测信号扰动不可忽视。研究中为抑制这种低频扰动对超微量注射检测的影响,设计液体阻尼器并采用增大水平阻尼与转动阻尼的方法使之得到有效地改善;进行皮升级注射量检测试验,结果表明所采用的基于原子力显微镜的超微量注射检测能够实现10～30pL微量注射检测。

The determination of microinjection volumes has receivedextensive attention in genetic and cell engineering. A new method for measuring the injection volumes is reported. The measurement is achieved by detecting the deflection of cantilever effected by the gravity of injected liquid, based on atomic force microscope （AFM） with nanometer resolution. The detecting system is sensitive to microvibration and the reliability of measuring result is remarkably influenced by disturbance. Disturbance factors are analyzed in droplet detection, a suppression device is adopted to suppress medium and high frequency disturbance, it has been observed that small swinging of suspension isolation system in horizontal direction cannot be ignored. In order to suppress the influence of this kind of low frequency for super micro-injection detection in the research, a liquid attenuator is designed and the horizontal and rotation damping are increased to improve isolation performance effectively. Detection experiment on picoliter-level injection is carried on and result indicates that ultra micro injection detection based on the atomic force microscope can realize 10-30 pL micro injection detection .