基于聚焦离子束的氮化硅纳米孔的制备和表征

Fabrication and Characterization of Solid Nanopores with Silicon Nitride Membranes by Focus Ion Beam

纳米孔是目前单分子测序的一项重要技术。作者以氮化硅绝缘材料为基底,采用微加工技术设计和制备了自支撑氮化硅悬空膜结构,然后利用聚焦离子束刻蚀悬空膜。通过优化聚焦离子束的系统参数,得到一系列孔径和锥度可控的纳米孔。通过扫描电镜和电学信号显示,该纳米孔具有很好的表面特性和伏安特性。当加入DNA分子时,电流瞬时下降,得到一系列明显、稳定的阻塞信号。说明该方法制备的纳米孔稳定可靠,可以用于不同生物分子的检测和分析。

Nanopores have become a kind of important tool for molecule detection at single molecular level. In this work, the authors demonstrated the fabrication of nanopores with silicon nitdde membranes by focus ion beam （FIB）. Firstly, the free-standing silicon nitride membranes were designed and etched by delicate techniques. Then, the free-standing membranes were drilled by focus ion beam. A set of nanopores with varied diameters and shapes were fabricated by FIB at different working conditions. These nanopores displayed high quality of morphologies and electric signals by means of SEM and electric measurements. In the presence of DNA, a series of evident current blockage appeared. Thus, nanopores prepared by this method are stable and sensitively, and they can meet the detection requirements for all kinds of biological molecules.