Gold Nanorod Translocations and Charge Measurement through Solid-State Nanopores
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- 作者：Kimberly E. Venta ; Mehdi B. Zanjani ; Xingchen Ye ; Gopinath Danda ; Christopher B. Murray ; Jennifer R. Lukes ; Marija Drndi膰
- 刊名：Nano Letters
- 出版年：2014
- 出版时间：September 10, 2014
- 年：2014
- 卷：14
- 期：9
- 页码：5358-5364
- 全文大小：479K
- ISSN：1530-6992
文摘
We study translocations of gold nanoparticles and nanorods through silicon nitride nanopores and present a method for determining the surface charge of nanorods from the magnitude of the ionic current change as nanorods pass through the pore. Positively charged nanorods and spherical nanoparticles with average diameters 10 nm and average nanorod lengths between 44 and 65 nm were translocated through 40 nm thick nanopores with diameters between 19 and 27 nm in 1, 10, or 100 mM KCl solutions. Nanorod passage through the nanopores decreases ion current in larger diameter pores, as in the case of typical Coulter counters, but it increases ion current in smaller diameter nanopores, likely because of the interaction of the nanopore鈥檚 and nanoparticle鈥檚 double layers. The presented method predicts a surface charge of 26 mC/m2 for 44 nm long gold nanorods and 18 mC/m2 for 65 nm long gold nanorods and facilitates future studies of ligand coverage and surface charge effects in anisotropic particles.