光流控系统中无损细胞的折射率检测与分选的研究

Technologies of cell detection and sorting, for example flow cytometry, play an important role in medicine, biology and many other disciplines. Based on the fluorescence probe method, measurement and purification of cells is achieved through complex flowsystem, optical and electrical system. Here, we propose a nondestructive and label-free method for refractive index measurement and sorting of cells utilizing on-chip optofluidic Fabry-Pérot (FP) cavity. The hydrodynamic focusing makes cells pass one by one through the detection region composed of FP cavity. The refractive index of cells can thus be determined from the interference curve shifts instantaneously recorded by the spectrometer. Category of the cells is distinguished by optical intensity, and then cells are re-directed into the desired microchannels by controlling microvalves. This optical characterization method does not only provide real-time detection and sorting, but also eliminate the cumbersome labeling procedure and contact manipulation of cells.

细胞的探测与分选技术，如流式细胞术，在医学、生物学等多个学科中都有着广泛而重要的用途。它们利用荧光探针，通过复杂的液流系统、光学系统及电系统来实现对细胞定量分析或纯化分选。本方案提出一种无损、免标记、快速光流控法布里-珀罗微腔的细胞折射率测量与分选技术。在光流控芯片系统中，利用微通道中流体的自聚焦效应使得细胞单个排列经过一对镀膜光纤端面构成的法布里-珀罗谐振腔，根据微腔透射谱线的变化可推得待测细胞的折射率；通过原共振波长处光强的变化来区分通过的细胞种类，利用微气阀控制微流体流向实现细胞分选。这种技术不仅可以实现对单细胞折射率的快速检测与分选，同时非接触式的操控避免了对细胞的标记或损伤。

本项目通过理论计算、微加工和实验探测等三方面的研究工作，在基于微流控系统检测微颗粒方面取得一定研究成果，为获得细胞无损检测与分选打下基础。具体主要研究成果包括：（1）在光纤布拉格光栅周期分布耦合模理论的框架下计算了红细胞和精子分别通过法布里-珀罗谐振腔时的光谱曲线。（2）利用聚二甲基硅氧烷（PDMS）制备了微流控芯片，并用于不同尺寸微颗粒的光学检测。（3）项目授权国家发明专利1项，实用新型专利1项，发表SCI收录源论文4篇，国际会议论文1篇。