Supporting Information
“Nano-Prism” Probe for Nano-Optical Applications
By Taekyeong Kim, Deok-Soo Kim, Byung Yang Lee, Zee Hwan Kim, and Seunghun Hong *
[*]
T. Kim, B. Y. Lee, and S. Hong
Department of Physics and Astronomy, Seoul National University
Shillim-Dong, Kwanak-Gu, Seoul, 151-747 (Korea)
E-mail: seunghun@snu.ac.kr
Fax: 82-2-884-3002
D. S. Kim, and Z. H. Kim
Department of Chemistry, Korea University
Anam-Dong, Seongbuk-Gu, Seoul 136-701 (Korea)
Figure S1. SEM image of an Al-coated probe with its end grinded off.
Figure S2. Ag nano-prism probe. (A) SEM image of a Ag nano-prism probe. (B) EDX
spectrum on the probe end (marked by a red spot in (A)). The “Si”, “Ag”, and “Cr” peaks
represent the silicon-made cantilever, Ag (~40 nm), and Cr adhesion layer (~10 nm),
respectively.
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Figure S3. Fabrication of Au-nanoparticle probes with high definition. In this process, a
grinded probe was coated with amine-terminated 3-aminopropyltriethoxysilane (APTES)
molecules by placing the probe in the APTES solution (1:500 v/v in ethanol) for 10 min.
When the probe was placed in the solution of 50-nm-diameter Au nanoparticles (Colloidal
Gold 50 nm, purchased from British BioCell Int.), negatively-charged nanoparticles were
attracted strongly to the positively-charged APTES SAM. Note that nanoparticles on the
probe side were completely removed after etching the Al layer.
Figure S4. AFM topography image taken on 100-nm-diameter Au nanoparticles on Si
substrates using a nano-prism probe. The image shows multiple images of similar shape for
the separated nanoparticles. The overlapped triangles indicate that two adjacent nanoparticles
on the substrate were imaged by the nano-prism probe in this case.
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Figure S5. Polarizaion dependent ANSOM images on 100-nm-diameter gold nanoparticles
taken with a nano-prism probe. (A) AFM topography image on a single nanoparticle. (B)
AFM topography image on two adjacent nanoparticles. (C) ANSOM image on the single
nananoparticle in (A) with a p-polarized incident light. (D) ANSOM image on the two
adjacent nananoparticles in (B) with a p-polarized incident light. (E) ANSOM image on the
single nananoparticle in (A) with a s-polarized incident light. (F) ANSOM image on the two
adjacent nananoparticles in (B) with a s-polarized incident light. The blue donut circle and
double arrowed line indicate a p-polarized incident light and a s-polarized incident light,
respectively. The yellow solid circles in D and F point to some differences in features in sand p-polarized ANSOM images.
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Figure S6. SEM image of a Au nano-prism probe after tapping-mode AFM and ANSOM
imaging. The Au nano-prism still remained at the end of the probe. It confirms that our Au
nano-prism probe was robust enough for stable SPM imaging.
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