Surface-enhanced resonance Raman scattering spectroscopy of single R6G molecules

• 来源期刊: 中国物理（英文版）
• 关键词: single-molecule spectroscopy surface-enhanced resonance Raman scattering spectral polarization Poisson distribution
• 年，卷（期）: 2006,（1）
• 页码范围: 126-131
• 页数: 6页
• 语种: 英文

摘要

Surface-enhanced resonance Raman scattering (SERRS) of Rhodamine 6G (R6G) adsorbed on colloidal silver clusters has been studied. Based on the great enhancement of the Raman signal and the quench of the fluorescence, the SERRS spectra of R6G were recorded for the samples of dye colloidal solution with different concentrations. Spectral inhomogeneity behaviours from single molecules in the dried sample films were observed with complementary evidences, such as spectral polarization, spectral diffusion, intensity fluctuation of vibrational lines and even "breathing" of the molecules. Sequential spectra observed from a liquid sample with an average of 0.3 dye molecules in the probed volume exhibited the expected Poisson distribution for actually measuring 0, 1 or 2 molecules. Difference between the SERRS spectra of R6G excited by linearly and circularly polarized light were experimentally measured.