Localized surface plasmon resonance nanosensor: A high-resolution distance-dependence study using atomic layer deposition

Alyson V. Whitney, Jeffrey W. Elam, Shengli Zou, Alex V. Zinovev, Peter C Stair, George C Schatz, Richard P. Van Duyne

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265 Citations (Scopus)


Atomic layer deposition (ALD) is used to deposit 1-600 monolayers of Al 2O 3 on Ag nanotriangles fabricated by nanosphere lithography (NSL). Each monolayer of Al 2O 3 has a thickness of 1.1 Å. It is demonstrated that the localized surface plasmon resonance (LSPR) nanosensor can detect Al 2O 3 film growth with atomic spatial resolution normal to the nanoparticle surface. This is approximately 10 times greater spatial resolution than that in our previous long-range distance-dependence study using multilayer self-assembled monolayer shells. The use of ALD enables the study of both the long- and short-range distance dependence of the LSPR nanosensor in a single unified experiment. Ag nanoparticles with fixed in-plane widths and decreasing heights yield larger sensing distances. X-ray photoelectron spectroscopy, variable angle spectroscopic ellipsometry, and quartz crystal microbalance measurements are used to study the growth mechanism. It is proposed that the growth of Al 2O 3 is initiated by the decomposition of trimethylaluminum on Ag. Semiquantitative theoretical calculations were compared with the experimental results and yield excellent agreement.

Original languageEnglish
Pages (from-to)20522-20528
Number of pages7
JournalJournal of Physical Chemistry B
Issue number43
Publication statusPublished - Nov 3 2005


ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

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