羊抗人IgG在金纳米通道中的迁移

Transport properties of goat anti-human IgG in gold nanotube membrane

以聚碳酸酯超滤膜为基板,用化学镀的方法在超滤膜上沉积金,制得直径在45nm左右的金纳米通道阵列,利用制得的金纳米通道阵列搭建离子电流测量平台,可实现对羊抗人IgG分子的浓度检测.当羊抗人IgG分子通过直径45nm的金纳米通道时,由于物理占位及表面电荷的影响,会引起离子电流发生变化;在KCl浓度为0.15mol/L(pH7.48)溶液中,IgG分子的物理占位对离子电流有阻塞作用,会导致电流减小,IgG浓度在1.8～18ng/mL范围内,减小量与浓度成线性关系;实现了对IgG的定量检测.KCl浓度降低到0.025mol/L时,由于IgG分子扩散层内反离子对通道内离子浓度的贡献占主导地位,从而造成离子电流随着IgG浓度增大而增大.

The preparation of Gold Nanotube Membranes was achieved by using electroless deposition of gold in the substrate of polycarbonate membranes with 100 nm diameter nanopores. The diameter of nanopore on the substrate can be reduced from 100 nm to about 45 nm due to the gold deposition. Using the nanotube membranes,a test rig was set up to measure the ionic current through the nanotube in KCl solution （pH 7.48）,as goat anti-human IgG molecules moved through the nanotube membrane,it will cause ionic current modulations. In the high strength KCl concentration 0.15 mol/L,the ionic current decreases because of the blocking effect of IgG molecules in nanotube. The decrement of current is in linear relationship with the concentration of IgG in the range of 1.8-18 ng/mL. When the concentration of KCl is reduced to 0.025 mol/L,the ionic current increases with the IgG concentration because the counterions that screening around the IgG molecules contribute a lot to the ionic current and cancel the blocking effect of the IgG molecules.