Two Particle Enhanced Nano Raman Microscopy and Spectroscopy

• DOI: 10.1021/nl070727m
• Publication Date: 2007-05-11T12:16:16Z
• Authors: Phillip Olk; Jan Renger; Thomas Härtling; Marc Tobias Wenzel; Lukas M. Eng
• Keywords: Particle (ecology)

The distance- and polarization-dependent near-field enhancement of two coupling metal nanoparticles (MNPs) is analyzed by means the novel scanning particle enhanced Raman spectroscopy (SPRM) technique. In contrast to single MNP experiments, between dissimilar MNPs as followed here leads a hot spot yielding an extra factor 17.6 20, proven both in experiment theory. Three-dimensional electric field calculations for our two-particle arrangements were performed using semianalytical multiple-multipole method. An excellent agreement found which we inspect interaction "scanning" 30 nm gold (Au30) "fixed" 80 Au (Au80). Au80 attached apex optical fiber manipulator exposed Gaussian focus high NA = 1.45 objective at λ 532 nm. A monolayer 1-octanethiol molecules covering serves prober when Au30 through focus. This constellation allows recording signatures from very low number well-confined molecules. Moreover, also spectral spatial dependence could be explored with superb sensitivity integration time.