Practical control of SERRS enhancement
Practical control of SERRS enhancement
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DOI：
10.1039/b506241a
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发表时间：
2006-01-01
影响因子：
3.4
通讯作者：
Laforest, N
中科院分区：
文献类型：
--
作者：
Cunningham, D;Littleford, RE;Laforest, N
使用表面增强共振拉曼散射（SERRS）可以进行定量和灵敏分析的证明促使了对使用胶体银作为基质的分析师控制范围内的主要变量的讨论和调查。以前的论文已经处理了至关重要的需要，以获得良好的化学吸附的分析物的表面，并报告了使用专门设计的染料的SERRS。变化最大的过程之一是胶体的聚集。在这里，我们研究了添加控制量的有机聚集剂，聚-L-赖氨酸，在浓度降低zeta电位在一个控制的方式，从而有助于聚集控制。在低浓度染料和无聚集剂的条件下，研究了银胶体的激发频率、表面等离子体共振频率与分子生色团最大吸光度频率之间的关系。在这些条件下，预期很少或没有聚集。增强的幅度强烈地依赖于分子发色团的频率以及等离子体共振频率。然而，当使用氯化钠来聚集胶体时，获得了更大的增强，并且对分子发色团的强烈依赖性在很大程度上消失。一个更广泛的增强亲。获得LE，其似乎与由聚集引起的特定增强过程的关系比与发色团的频率的关系更大。然而，SERRS的总增强高于Sers，因此表明发色团对该过程仍然很重要。
The demonstration that quantitative and sensitive analysis can be carried out using surface enhanced resonance Raman scattering (SERRS) prompted a discussion and investigation of the main variables which are within the control of the analyst using colloidal silver as the substrate. Previous papers have dealt with the crucial need to obtain good chemisorption of the analyte to the surface and have reported the use of specially designed dyes for SERRS. One of the most variable processes is the aggregation of the colloid. Here, we investigate the addition of controlled amounts of an organic aggregating agent, poly-L-lysine, at concentrations which reduce the zeta potential in a controlled manner, thus aiding aggregation control. The relationship between the excitation frequency, the surface plasmon resonance frequency of the silver colloid and the frequency of the maximum absorbance of the molecular chromophore is studied using low concentrations of dye and no aggregating agent. Under these conditions, little to no aggregation is expected. The magnitude of the enhancement is strongly dependent on the frequency of the molecular chromophore as well as the plasmon resonance frequency. However, when sodium chloride is used to aggregate the colloid, a larger enhancement is obtained and the strong dependence on the molecular chromophore largely disappears. A much broader enhancement pro. le is obtained which appears to be related more to the specific enhancement processes caused by aggregation than the frequency of the chromophore. However, the total enhancement for SERRS is higher than for SERS thus indicating that the chromophore is still important to the process.