Abstract

We demonstrate here a surface impedance imaging technique based on sensitive dependence of surface plasmon resonance (SPR) on local surface charge density. By applying a potential modulation to a sensor surface, we are able to simultaneously obtain three images: the dc component and the amplitude and phase of the ac component. The dc image measures local molecular binding activity on the surface, as found in the conventional SPR imaging technique, and the ac images are directly related to the local impedance of the surface. Our experimental data can be analyzed quantitatively in terms of the simple free electron gas model for the sensor surface and the Randles equivalent circuit model for interfacial impedance.

Original languageEnglish (US)
Pages (from-to)5146-5151
Number of pages6
JournalAnalytical chemistry
Volume80
Issue number13
DOIs
StatePublished - Jul 1 2008

ASJC Scopus subject areas

  • Analytical Chemistry

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  • Cite this

    Foley, K. J., Shan, X., & Tao, N. (2008). Surface impedance imaging technique. Analytical chemistry, 80(13), 5146-5151. https://doi.org/10.1021/ac800361p