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作为一种重要的单分子检测技术,纳米孔的表面特性至关重要。作者利用聚焦离子束刻蚀方法制备得到了一系列形貌可控的氮化硅纳米孔,并对纳米孔进行了表面改性修饰。结果发现,经过化学处理的氮化硅表面具有大量的硅羟键,非常利于和硅烷发生反应,从而在纳米孔表面引入活性基团,如氨基、正辛基和巯基等。通过对修饰有不同硅烷的纳米孔的表面特性和电导特性的研究发现,当硅烷分子将氮化硅表面的硅羟键变为其它功能基团时,材料表面电荷会发生变化,亲、疏水性也发生变化,从而导致电渗流的改变,影响纳米孔的电导。同时,修饰硅烷分子后,材料表面的电荷特性发生了改变,也会导致纳米孔器件的膜电容减小,介电噪声降低。
As an important single-molecule detection technique, the surface properties of nanopores are of crucial importance. The authors prepared a series of silicon nitride nanopores with controlled morphology by focused ion beam etching, and modified the surface of the nanopores. The results showed that the surface of the chemically treated silicon nitride has a large number of silicon-hydroxyl bonds and is very conducive to react with the silane to introduce active groups on the surface of the nanopore, such as amino group, n-octyl group and mercapto group. Through the study on the surface properties and conductivity of the modified nano-holes with different silane, it is found that when the silanol molecules change the silanol bonds on the surface of silicon nitride into other functional groups, the surface charge of the material will change, and the hydrophilicity and hydrophobicity Also changes, resulting in changes in the electroosmotic flow, affecting the conductance of nanopores. At the same time, the modified silane molecules, the material surface charge characteristics have changed, will lead to nano-pore device membrane capacitance decreases, dielectric noise reduction.