Direct visualization of a surface-enhanced Raman spectroscopy nano-gap via electrostatic force microscopy: Dependence on charge transfer from the underlying surface nano-gap distance
| Autor: | Sung-Gyu Park, Dongho Kim, Namhyun Choi, Won-Hwa Park, Jaebum Choo, Moon Seop Hyun, Mijeong Kang |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Electrostatic force microscope General Physics and Astronomy 02 engineering and technology Substrate (electronics) 010402 general chemistry 01 natural sciences chemistry.chemical_compound symbols.namesake Etching (microfabrication) Sputtering Nano Polyethylene terephthalate technology industry and agriculture Surfaces and Interfaces General Chemistry Surface-enhanced Raman spectroscopy 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Surfaces Coatings and Films chemistry Chemical physics symbols 0210 nano-technology Raman scattering |
| Zdroj: | Applied Surface Science. 479:874-878 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/j.apsusc.2019.02.034 |
| Popis: | We have visualized surface-enhanced Raman scattering (SERS) nano-gap domains with electrostatic force microscopy (EFM). We constructed the SERS substrate using reactive-ion etching of a polyethylene terephthalate (PET) film, with subsequent sputtering of Au onto the etched PET. Because the nano-gap is more strongly charged than the native Au-nanoparticle (NP) surface, we can identify the SERS nano-gap due to the longer dwell time of the tapping EFM tip and the related phase shift of the signal. This produces a differentiating image contrast between the SERS nano-gap and the Au NP surface, with a spatial resolution of ~14 nm. More specifically, differences in the mode-independent Raman-signal enhancement and the peak shift of an adsorbed malachite green isothiocyanate (MGITC) molecule are only observed in the smaller SERS nano-gap (found in the surface with Ar+-sputtered Au nano-pillars). We interpret this in terms of the differing morphologies of the underlying Au substrates and the related mechanical compressive strains, which result in charge transfer (CT)-based single-molecule Raman-reporter detection sensitivity. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect