Studies of Ionic Current Rectification Using Polyethyleneimines Coated Glass Nanopipettes

• Published in: Analytical chemistry (Washington) Vol. 84; no. 13; pp. 5565 - 5573
• Main Authors: Liu, Shujuan, Dong, Yitong, Zhao, Wenbo, Xie, Xiang, Ji, Tianrong, Yin, Xiaohong, Liu, Yun, Liang, Zhongwei, Momotenko, Dmitry, Liang, Dehai, Girault, Hubert H, Shao, Yuanhua
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 03-07-2012
• Subjects: Analytical chemistry; Biological and medical sciences; Cell membranes. Ionic channels. Membrane pores; Cell structures and functions; Chemistry; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Glass; Molecular and cellular biology; Nanoparticles; Scattering; Light scattering; Size; Glass; Ionic channel; Concentration; Ionic current; Method; Pipette; Dynamics; Size effect; pH; Detection; Polyethylene imine
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac3004852

The modification of glass nanopipettes with polyethyleneimines (PEIs) has been successfully achieved by a relatively simple method, and the smallest tip opening is around 3 nm. Thus, in a much wider range of glass pipettes with radii from several nanometers to a few micrometers, the ion current rectification (ICR) phenomenon has been observed. The influences of different KCl concentrations, pH values, and tip radii on the ICR are investigated in detail. The sizes of PEIs have been determined by dynamic light scattering, and the effect of the sizes of PEIs for the modification, especially for a few nanometer-pipettes in radii, is also discussed. These findings systemically confirm and complement the theoretical model , and provide a platform for possible selectively molecular detection and mimic biological ion channels.