Abstract Two different silver colloids were synthetized using the reducing agents sodium citrate (Lee-Meisel method) and hydrochloric hydroxylamine (Leopold-Lendl method). The properties of these colloids were evaluated by investigating a selection of 25 synthetic organic dyes and pigments that belong to different chemical classes and whose Raman spectra are usually poor or are overwhelmed by fluorescence. The observed changes in the SERS spectra acquired using both colloids were evaluated and interpreted by taking into account that enhancement of the Raman signal is influenced by the localised plasmon resonance on the silver nanoparticles as well as by the chemical affinity and molecule orientation on the metal substrate. The morphology and plasmon resonance of the single nanoparticles were characterised by means of UV–Vis absorption spectroscopy. The results revealed significant differences in terms of stability and reproducibility. Furthermore, the sensitivity of the colloids and the reproducibility of the different measurements were evaluated in terms of the Raman shift and signal intensity. SERS spectra of triarylcarbonium (BV 14, BG 1, AB 110, AB 83, PB 1, PG 1) and xanthene colourants without halogen substituents (BV 10, PV 1, BR 1, PR81) as well as the nitro dye AY 24 were very reproducible with both colloids; however, others, such as brominated xanthene dyes (AR 87, AR 91), thioindigo pigments (PR 88, PR 181) and anthraquinone colourants, may present different spectral features depending on the colloid used, which should be taken into account when interpreting unknown spectra. The hydroxylamine-reduced colloid, besides being a reproducible and easy-to-produce SERS substrate, gave satisfactory spectra with all the SERS-active dyes and pigments that were examined. Based on the results, we assume that the hydroxylamine-reduced substrate is the best choice for acquiring spectra for a future SERS database for cultural heritage (CH) applications.

中文翻译：

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面向文化遗产中合成有机着色剂的表面增强拉曼散射 (SERS) 光谱数据库。使用不同金属基材对光谱的影响

摘要 使用还原剂柠檬酸钠（Lee-Meisel 法）和盐酸羟胺（Leopold-Lendl 法）合成了两种不同的银胶体。通过研究属于不同化学类别且其拉曼光谱通常较差或被荧光淹没的 25 种合成有机染料和颜料，对这些胶体的性质进行了评估。考虑到拉曼信号的增强受银纳米颗粒上的局域等离子体共振以及金属基材上的化学亲和力和分子取向的影响，对使用两种胶体获得的 SERS 光谱观察到的变化进行了评估和解释. 通过紫外-可见吸收光谱表征单个纳米颗粒的形态和等离子体共振。结果显示在稳定性和重现性方面存在显着差异。此外，还根据拉曼位移和信号强度评估了胶体的灵敏度和不同测量的再现性。三芳基碳鎓（BV 14、BG 1、AB 110、AB 83、PB 1、PG 1）和不含卤素取代基的呫吨着色剂（BV 10、PV 1、BR 1、PR81）以及硝基染料 AY 24 的 SERS 光谱分别为两种胶体的重现性都很好；然而，其他物质，如溴化呫吨染料（AR 87、AR 91）、硫靛颜料（PR 88、PR 181）和蒽醌着色剂，可能会根据所使用的胶体呈现不同的光谱特征，在解释未知时应予以考虑光谱。羟胺还原胶体，除了是一种可重现且易于生产的 SERS 底物外，对所有被检查的 SERS 活性染料和颜料给出了令人满意的光谱。基于这些结果，我们假设羟胺还原底物是获取用于文化遗产 (CH) 应用的未来 SERS 数据库的光谱的最佳选择。