共查询到19条相似文献,搜索用时 93 毫秒
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利用激光刻蚀法制备了具有化学纯净表面的银岛膜,该岛膜有很好的表面增强特性。利用表面增强拉曼光谱和表面增强红外光谱对胸腺嘧啶分子在银岛膜表面的吸附状态进行了对比研究。表面增强拉曼光谱中CN和C—O伸缩振动模式的出现表明胸腺嘧啶分子由原来的酮式结构变成了烯醇式结构;C(4)O伸缩振动谱带明显增强和N(3)的去质子化异构体特征峰的存在证明胸腺嘧啶分子是通过O(8)和N(3)的共同作用倾斜地吸附在银岛膜表面。对10-5 mol.L-1胸腺嘧啶在银岛膜表面上的红外光谱利用欧米采样器进行了反射法测量,发现其红外吸收增强了200倍。红外信号分析的结果支持了胸腺嘧啶分子通过O(8)与银表面发生相互作用的论断,同时也可得出胸腺嘧啶倾斜地吸附在银岛膜表面的结论。 相似文献
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报道了S-胸腺嘧啶-L-半胱氨酸的FTIR光谱,及其固态、饱和液态的FT-Raman光谱.通过红外与拉曼光谱的结合,对其分子结构中各基团的振动情况进行了较为全面的解析;实验发现,该化合物在银胶上的最佳SERS的浓度为10-4mol·L-1,氨基峰在酸性条件下增强,羧基峰在碱性条件下增强,而其他基团峰随pH值的改变变化不大.依据SERS作用机理和规律,推测S-胸腺嘧啶-L-半胱氨酸在银胶表面的吸附是通过硫原子、羧基、氨基、胸腺嘧啶环和其中的氮原子与银原子配位,且胸腺嘧啶环是倾斜着与银纳米颗粒相吸附;该吸附模型的建立为拉曼光谱更深入研究PNA、多肽及其他生物分子提供了十分重要的信息和有益的参考. 相似文献
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低能离子注入引起生物体诱变效应的机理一直是人们关注的问题.DNA是辐射作用的靶,文章对低能氮离子注入胸腺嘧啶后的样品进行了XPS研究,发现注入后C,N,0三元素的质量百分比的相对值发生了变化,N,O含量下降,C含量明显增加.精细结构分析发现,O(ls)峰的峰位发生偏移,N(1s)峰由注入前的单峰变为3个峰,C(ls)峰由注入前的2个峰变为注入后的单峰,说明注入后各元素所处的化学环境和物理结构都发生了较大改变,N 注入能导致胸腺嘧啶分子结构的破坏,改变原结构状态. 相似文献
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采用基于密度泛函理论的第一性原理平面波赝势方法研究了SrTiO3(001)表面上Au和N原子间相互作用的微观机理.通过比较分析N置换表面层O原子前后SrTiO3(001)表面吸附Au原子体系的相关能量和电子结构,发现SrTiO3(001)表面吸附Au原子和N替代表面层O原子的置换过程二者之间存在明显的"协同效应",即N原子置换SrTiO3(001)表面层O原子的过程增强了相应表面吸附Au原子的稳定性,而SrTiO关键词:
表面结构
相互作用
第一性原理 相似文献
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尝试使用高分子材料作为银溶胶的稳定剂,以吡啶作为内标化合物研究胸腺嘧啶浓度与其SERS信号强度的关系。在胸腺嘧啶的浓度为2×10-4~1×10-3 mol·L-1的范围内,谱峰强度之比与胸腺嘧啶的浓度之间呈现良好的线性关系,线性回归方程为y=3.143x+0.348 7, 线性相关系数R2=0.975 4。 相似文献
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用近红外傅里叶拉曼光谱研究了苏丹红Ⅲ分子在覆银纳米颗粒的抛光铝片表面上的吸附行为,得到了一系列高质量的增强拉曼散射(SERS)谱图。对苏丹红Ⅲ分子在银胶溶液、覆银滤纸、覆银粗糙铝片上的SERS谱进行比较,结果表明苏丹红Ⅲ分子在各基底上与银纳米颗粒表现出不同的吸附行为。在银胶溶液中,苏丹红Ⅲ分子主要是通过N=N双键吸附在银纳米颗粒上的;在沉积了银纳米颗粒的滤纸表面,同样地,主要是由N=N双键吸附;而在沉积了银纳米颗粒的抛光铝片表面,不仅N=N双键参与了吸附,苏丹红Ⅲ分子中的羟基与银颗粒有相互作用,并且铝片上的氧化铝颗粒也可能吸附了苏丹红Ⅲ分子。 相似文献
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Dependence of surface-enhanced Raman scattering (SERS) from Calf thymus DNA on anions is investigated.With the silver colloid,the bands at 732,960 and 1333 cm-1 for adenine (A),1466 cm-1 for deoxyribose,and 1652 cm-1 for the C=O group of thymine (T) are observably enhanced.With the presence of the Cl- or SO42- anions,the bands at 732 and 1326/1329 cm-1 for the symmetric stretching and skeletal vibrational modes of adenine (A) are dramatically enhanced,and the enhancement effect with the SO24- ion is more than that with the Cl- ion.The experimental results show that the DNA molecule can be adsorbed on the silver colloid particles through the C6N and N7 of adenine (A),the C=O of thymine (T) and deoxyribose.Moreover,the formed hydrogen bonding of the Cl- or S2O4- ions to the C6NH2 group of adenine (A) can induce larger C6N electronegativity,which is favor for the C6N/N7 cooperative adsorption on the (Ag) n colloid particles. 相似文献
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Hui Chu Haifeng Yang Shuangyan Huan Weiqi Lin Guoli Shen Ruqin Yu 《Journal of Raman spectroscopy : JRS》2007,38(3):295-300
The adsorption modes of 4‐amino‐3‐hydrazino‐5‐mercapto‐1,2,4‐trizole (purpald) self‐assembled monolayers (SAMs) formed on SERS‐active silver and gold electrodes were comparatively studied using surface‐enhanced Raman scattering (SERS), and the self‐assembling procedures were investigated by the Raman mapping technique. Purpald SAMs adopted a titled orientation with S, N2 atoms anchoring to the silver electrode and the N7H2 close to the surface, whereas purpald stood up on the gold electrode through S, N5 atoms and with N8H2 adjacent to the surface. The density functional theory (DFT) at the level of B3LYP was performed to help explain their different adsorption behaviors on the silver and gold electrodes. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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负电性纳米银溶胶SERS活性及稳定性的比较研究 总被引:1,自引:0,他引:1
用单宁还原硝酸银可制得表面带负电的、对阳离子型分子具有较强SERS效应的纳米银。为了进一步测试负电性纳米银溶胶的SERS活性及稳定性,在室温下用制针剂的封装机将样品(old NCS)封装并保存。两年后与新制备的负电性纳米银溶胶(new NCS)比较,用透射电镜观测发现old NCS与new NCS相比银粒子尺寸增大;用紫外可见吸收光谱测定old NCS的吸收峰为431 nm,new NCS的吸收峰为418 nm,old NCS与new NCS相比吸收峰发生红移。为比较old NCS及new NCS的SERS活性选取阳离子型分子、中性分子及阴离子型分子作为测试分子,用拉曼光谱仪测试这些分子在两种纳米银上的SERS谱,结果发现,阳离子型分子碱性品红、中性分子吖啶橙在old NCS及new NCS上SERS较强,阳离子型分子亚甲基蓝在old NCS上与在new NCS上相比SERS较弱,阴离子型分子苯甲酸在old NCS及new NCS均未观察到SERS信号。 相似文献
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Single‐molecule detection by surface‐enhanced resonance Raman scattering (SERRS) spectroscopy has been demonstrated for a variety of molecules. The detection of single molecules that do not have a resonance contribution, SERS, has been shown in the case of adenine. However, when colloidal particles isolated on planar substrates are used as the enhancing medium, the presence of anomalous signals significantly complicates the analysis of the spectra. Selection of a silver colloid that minimizes these spurious signals should improve the ultra‐sensitive detection of non‐resonant single molecules by SERS. A range of silver colloids, prepared by different methods, were investigated with respect to their activity and stability. Minimal anomalous signals were obtained from hydroxylamine‐reduced silver colloids, which suggests that this colloid will be better for ultra‐sensitive SE(R)RS experiments compared to the more common citrate‐ and borohydride‐reduced silver colloids. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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电解法制备纳米银溶胶及其SERS活性研究 总被引:3,自引:1,他引:2
分别用柠檬酸三钠溶液、硝酸银和聚乙烯醇混合液作为电解液,用银棒作为电极,加上7 V直流电压,通电1 h,用电解方法得到了纳米银溶胶。为测试该纳米银溶胶是否具有表面增强拉曼散射1(SERS)活性,选用了阳离子型分子碱性品红(Fuchsine basic)、亚甲基蓝(Methylene blue),阴离子型分子苯甲酸(Benzoic acid),甲基橙(Methyl orange)、中性分子吖啶橙(Alcidine orange)、苏丹红(Sudan red)作为测试分子,进行SERS研究,结果发现用两种电解液制备的纳米银都具有很强的SERS活性,但用硝酸银和聚乙烯醇混合液作为电解液制备的纳米银溶胶具有更广泛的SERS 活性。在该方法制备的纳米银上,得到了在常规方法制备的胶态纳米银上及用柠檬酸三钠溶液作为电解液制备的纳米银上得不到的甲基橙分子的SERS谱,对可能的原因进行了讨论。 相似文献
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Katarzyna M. Marzec Bartlomiej Gawel Wieslaw Lasocha Leonard M. Proniewicz Kamilla Malek 《Journal of Raman spectroscopy : JRS》2010,41(5):543-552
This paper discusses and compares molecular interactions of rhodanine (Rd), the heterocyclic compound containing N, S, and O atoms, with two forms of silver species, i.e. Ag(I) ions and silver nanocolloidal particles. Vibrational spectroscopic and powder crystallography studies on coordination of Ag(I) ions in the solid state, supported by density functional theory, clearly indicate complexation through the nitrogen (the deprotonated imino group) and exocyclic sulfur atoms. Molecules of the complex are arranged in a one‐dimensional infinite polymeric chain structure that intertwines to give a helix motif. On the other hand, adsorption geometry of Rd on the silver surface was determined by using surface‐enhancement Raman scattering (SERS) spectroscopy. Observed differences between the SERS and the normal Raman spectra of Rd suggest that Rd adsorbs on the silver species after the rearrangement of the keto‐thione form into the enol‐thiol tautomer in acidic and neutral solutions. This leads to adsorption on this silver species through the thiolate ion. On the other hand, the alkaline pH forces first N‐deprotonation of Rd, and, in consequence, the obtained anion of the keto‐thione form interacts with the silver surface as a result of the presence of lone pairs of nitrogen and sulfur atoms, similar to the case discussed for the solid state. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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用Nd:YAG激光器在二次去离子水中烧蚀银片,制备出了尺度分布均匀、并且具有很好的稳定性的"化学纯净"的Ag胶体系,并在电化学体系中将这种银胶沉积在粗糙的银电极表面,研究了胞嘧啶分子吸附在沉积Ag纳米颗粒电极表面随电极电位改变的表面增强拉曼光谱(SERS)。分析表明:(1)沉积银纳米颗粒的电极将金属电极与金属溶胶体系各自的优势很好的结合起来,形成了一种高效的SERS活性基底。(2)胞嘧啶在沉积银颗粒的电极表面以N3位竖直吸附,并且随着电位的负移,大多数SERS峰的位置发生了红移,表明胞嘧啶在电极表面吸附作用减弱。 相似文献
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Ag_2O胶体粒子的自组装单层膜和多层膜 总被引:4,自引:0,他引:4
本文制备了Ag2O胶体粒子的自组装单层膜和多层膜。运用接触角测量、红外吸收光谱和紫外可见吸收光谱等手段证实了Ag2O胶体粒子能够组装在具有羧基的基底上,在有1,18 十八烷基二羧酸做为交联剂的情况下还可形成自组装多层膜 相似文献