The 78th JSAP Autumn Meeting, 2017

Presentation information

Oral presentation

4 JSAP-OSA Joint Symposia 2017 » 4.1 Plasmonics

[5a-A410-1~8] 4.1 Plasmonics

Tue. Sep 5, 2017 9:00 AM - 11:45 AM A410 (410)

Prabhat Verma(Osaka Univ.), Hiromi Okamoto(IMS)

11:15 AM - 11:30 AM

[5a-A410-7] DUV nano-Raman microscopy with plasmonic tip

Atsushi Taguchi1, Kohta Saitoh1,2, Satoshi Kawata1,2 (1.Osaka University, 2.Serendip Research)

Keywords:TERS in DUV, aluminum tip, resonance Raman

Tip-enhanced Raman spectroscopy (TERS) is a unique and indispensable imaging technique which enables analysis of nano-materials with a spatial resolution of a few tens of nanometers together with a strong enhancement of weak Raman signals from the nanometric volume of a sample [1]. The strong enhancement and photon localization is realized with plasmonic metallic tips [2]. While gold and silver, commonly used tip materials, are effective plasmonic metals in the visible wavelengths, in the deep UV (DUV) wavelength region, these metals behave absorptive dielectrics but not as metal. This has limited the use of TERS in the visible wavelengths. However, DUV is an interesting wavelength region in spectroscopy and microscopy because molecules such as nucleotides and proteins show characteristic resonance Raman scatterings, which can be effectively combined with plasmonic tip-enhancement.
With an aluminum tip instead of gold and silver tips, we have demonstrated TERS in the DUV [3]. We reported an enhancement factor of ~1,300 with adenine nanocrystal as a sample, where the resonance Raman scattering of samples were excited with 266 nm laser wavelength [3]. The localized plasmon resonance of aluminum and indium nanoparticles was investigated and shown to have plasmonic resonance in the DUV [4,5].
In this presentation, we will show the results of our recent development of DUV-TERS microscopy. Instrumentations of DUV-TERS microscopy will be shown. The DUV-TERS enhancement of graphene, carbon nanotubes, and adenines will be shown together with metal structures at the tip apex characterized by SEM observations.

References
[1] Satoshi Kawata, Taro Ichimura, Atsushi Taguchi, Yasuaki Kumamoto, Chem. Rev. 117 (2017) 4983.
[2] Atsushi Taguchi, Jun Yu, Prabhat Verma, Satoshi Kawata, Nanoscale 7 (2015) 17424.
[3] Atsushi Taguchi, Norihiko Hayazawa, Kentaro Furusawa, Hidekazu Ishitobi, Satoshi Kawata, J. Raman Spectrosc. 40 (2009) 1324.
[4] Atsushi Taguchi, Yuika Saito, Koichi Watanabe, Song Yujian, Satoshi Kawata, Appl. Phys. Lett. 101 (2012) 081110.
[5] Yasuaki Kumamoto, et al. ACS Photonics 1 (2014) 598.