11:00-11:45

Remote excitation of SERS/Fluorescence on sub-diffraction limited plasmonic waveguide

Metal nano-structures have attracted a lot of attention these decades because of the exceptional optical properties arising from localized surface plasmons resonances. The optical response of metal nano-structures strongly depends on their structure, size, shape, aggregation state, and local environment. The extraordinary properties of surface plasmons have resulted in the use of metal nano-structures for waveguides^[1], plasmonic optics^[2], etc. Furthermore, the confined localized electromagnetic field connected to LSPRs leads to a highly effective enhancement of both surface enhanced fluorescence (SEF)^[3] and Raman scattering (SERS)^[1]. This has resulted in the development of ultra-sensitive SERS-based bio-sensing schemes. Recently also SEF has been exploited for fluorescence-based sensing in biology.

It will be demonstrated that SPPs launched by optical excitation at an end of silver nanowire (50-150 nm diameter) can excite SERS or SEF at many micrometers along the wire due to the SPPs waveguide effect^[1,2]. This remote excitation of SERS (RE-SERS) and SEF (RE-SEF) provides signal with very little background compared to when using direct excitation. The ability to transfer SERS/SEF excitation over several microns, through a sub-diffraction limited structure, will be discussed with respect to potential super-resolution imaging applications.

References

[1] J. A. Hutchison, S. P. Centeno, H. Odaka, H. Fukumura, J. Hofkens, H. Uji-i Nano Letters. 2009, 9, 995-1001.

[2] H. Lin, T. Ohta, A. Paul, J. A. Hutchison, K. Demid, O. Lebedev, G. Van Tendeloo, J. Hofkens, H. Uji-i Journal of Photochemistry and Photobiology A: Chemistry. 2011, 221, 220-223.

[3] Hongzhen Lin, Silvia P. Centeno, Liang Su, Bart Kenens, Susana Rocha, Michel Sliwa, Johan Hofkens, and Hiroshi Uji-i, ChemPhysChem DOI: 10.1002/cphc.201100743.

Speaker

Prof. Hiroshi Uji-i, Department of Chemistry, Katholieke Universiteit Leuven, Belgium

Chair

Dr. Katsuhiko Ariga, Principal Investigator, MANA, NIMS