一种新颖的微纳流体器件制造方法与痕量富集应用

A Novel Method for Fabricating Micro-Nanofluidic Devices and Its Application to Trace Enrichment

建立了一种利用光致聚合反应制备微纳流体器件的新方法,并开展了相应的痕量富集实验研究:建立描述光致聚合反应中引发剂分解、自由基消耗、聚合反应等的理论模型,利用COMSOL软件计算分析了微尺度凝胶光致聚合反应过程,获得凝胶纳米筛宽度随曝光时间和光强的变化规律;以倒置荧光显微镜为平台,通过聚焦和分光等控制手段,在微流道的特定区域实现孔密度可调的凝胶纳米筛集成,形成微纳流控芯片;以Poisson-Nernst-Planck模型为基础,对纳流体电动富集过程进行计算,确定纳孔密度与富集倍率的关系;利用制备的芯片开展纳流体电动富集实验,发现前驱液中单体丙烯酰胺与交联剂N,N'-亚甲基双丙烯酰胺质量比为9∶1时,对痕量异硫氰酸荧光素(Fluorescein isothiocyanate,FITC)小分子的富集倍率达到600倍。

A new method for fabricating micro-nanofluidic devices through photopolymerization was developed and related experimental research on trace enrichment was undertaken. COMSOL software was utilized to calculate and analyze the gel photopolymerization process in microscale and a mathematical model of photopolymerization including photoinitiator decomposition, radical consumption, polymerization, etc. , was established. The influence of the exposure time and the light intensity on gel nanosieve width was investigated. With an inverted fluorescence microscope, the micro-nanofluidic chip was prepared by integrating pore density-tunable gel nanosieves into specific areas of the microchannels through focusing, beam splitting and other control means. Based on the Poisson-Nernst-Planck model, the process of nanofluid-based electrokinetic enrichment process was simulated numerically, and the relationship between nanopore density and concentration ratio was investigated. Utilizing the prepared chips, the experiments of nanofluid-based eleetrokinetic enrichment were performed and the enrichment ratio of fluorescein isothiocyanate （FITC） could reach 600-fold as the mass ratio of the monomer aerylamide and the erosslinker N,N＇-methylenebisacrylamide was 9： 1.