用于水溶液中扫描隧道显微镜的聚二甲基硅氧烷涂层针尖的制备。

Preparation of tips coated with poly(dimethylsiloxane) for scanning tunneling microscopy in aqueous solutions.

作者信息

Kuroda Mizuki, Nishino Tomoaki

机构信息

Department of Physics and Electronics, Graduate School of Engineering, Osaka Prefecture University, Sakai, Osaka 599-5831, Japan.

出版信息

Rev Sci Instrum. 2011 Jun;82(6):063707. doi: 10.1063/1.3602330.

DOI:10.1063/1.3602330

PMID:21721702

Abstract

A simple and reliable method for preparing tips coated with poly(dimethylsiloxane) (PDMS) for scanning tunneling microscopy (STM) in aqueous solutions is reported. Au STM tips were dip-coated with PDMS and subsequently cured. The coated tips were characterized by scanning electron microscopy, energy dispersive x-ray spectroscopy, and voltammetry. We show that the PDMS layer smoothly covers the tip surface except for its very apex. These tips enable atomically resolved imaging of a sample surface and measurement of single-molecule conductance below 1.0 nS with STM in aqueous solutions. Because of the superior compatibility of PDMS with organic solvents, the PDMS-coated tips would be useful for preparing molecular tips via their chemical modification in such solvents, enabling chemically selective imaging of a single molecule in water.

摘要

报道了一种用于制备在水溶液中用于扫描隧道显微镜（STM）的聚二甲基硅氧烷（PDMS）涂层针尖的简单可靠方法。金STM针尖用PDMS浸涂，随后固化。通过扫描电子显微镜、能量色散X射线光谱和伏安法对涂覆的针尖进行了表征。我们表明，除了针尖的最顶端外，PDMS层能平滑地覆盖针尖表面。这些针尖能够在水溶液中用STM对样品表面进行原子分辨成像，并测量低于1.0 nS的单分子电导。由于PDMS与有机溶剂具有优异的相容性，PDMS涂覆的针尖将有助于通过在这类溶剂中进行化学修饰来制备分子针尖，从而实现水中单个分子的化学选择性成像。