Probing R6G single molecules by surface-enhahced resonance Raman scattering

以共焦显微系统为平台，研究了不同浓度的R6G银溶胶的表面增强共振拉曼散射（SERRS）光谱，结果表明不同浓度溶液中的R6G分子表现出了不同的光谱特性。在浓度为10^-13mol·L^-1的R6G银溶胶中得到了R6G单分子的表面增强共振拉曼散射光谱，观察到了一些光谱非均匀变化现象，如谱色散、谱线的强度起伏、拉曼谱的偏振化以及分子的闪烁等，并对这些现象进行了分析，证明得到的是R6G单分子的SERRS光谱。文章还对单分子检测中的一些关键问题进行了分析与讨论，确定了单分子SERRS光谱检测的适当条件。R6G was incubated in three kinds of silver colloid with different low concentrations, and its surface-enhanced resonance Raman scattering (SERRS) was studied with a confocal microscopy system. Each sample exhibited different spectrum character. At the single-molecule level the SERRS-spectra were recorded in 10-(13) mol (circle) L(-1)dye colloidal solution. Some spectral inhomogeneous behavior was recorded such as spectral diffusion, intensity fluctuation of vibrational lines and spectral polarization, and even on/off blinking and splitting of some lines within the spectrum of one molecule. Polarization of excitation light and background subtraction of signal have an important influence on the SERRS spectra detection of single-molecule, which was analyzed in the present paper