欢迎您！东篱公司
退出
-
申报数据库
-
立项数据库
-
成果数据库
-
项目获奖数据库
中文摘要：
获得了不同浓度下亚甲基蓝（methylene blue，MB）溶液在银溶胶中的表面增强拉曼光谱。结果表明： 亚甲基蓝分子与银纳米粒子高浓度下物理吸附为主，低浓度下化学吸附为主;不同浓度下存在不同的吸附取向，即高浓度下为“直立”取向，低浓度为“平躺”取向。通过观察低浓度下MB在银胶中吸附时间对谱图的影响，得知低浓度下吸附取向不随时间发生变化。应用密度泛函（DFT）方法在B3LYP/6-31＋G^＊和LANL2DZ基组水平上对亚甲基蓝阳离子（MB^＋）及MB^＋与Ag原子形成的不同构型体系进行了结构优化和频率计算。实验与理论计算结果表明，MB^＋有可能通过N—Ag和S—Ag与Ag原子形成两种较强的吸附构型。电荷布居分析表明，与S原子相比，芳香环上的N原子更易与Ag发生相互作用。还对实验观察到的部分谱峰及它们的振动模式作出了初步归属和讨论。
英文摘要：
Surface-enhanced Raman spectra of methylene blue （MB） at different concentrations in silver colloid were obtained. The results indicate that the physical adsorption is dominant at high concentration while the chemical adsorption is the main fashion at relatively low concentration; there are different adsorption orientations at different concentration： MB^＋ molecule is perpen dicular to the surface of silver nanoparticle at high concentration and adopts a parallel orientation on the surface of nanoparticle atlow concentration. The effect of adsorbing time of MB molecule in Ag colloid was investigated and the adsorption dynamics study shows that the parallel orientation at low concentration does not change with the adsorbing time increasing. Density functional theory （DFT） calculations at the level of B3LYP/6-311＋G ^＊ （for C, S, N, H）/LANL2DZ （for Ag） were employed to optimize the structures and predict Raman frequencies of MB^＋ and various MB^＋-Ag complexes. The results of experiments and calcula-tions suggest that the silver atom prefers to be bound to N and S atoms in the aromatic ring, and thus two different complexes are formed, i.e. conformer N-Ag and conformer S-Ag. Moreover, the Mulliken charge population analysis indicates that N atom in the aromatic ring prefers to interact with Ag than S atom does. Finally, the Raman frequencies observed in the experiments and their vibrational modes were tentatively assigned and discussed.
同期刊论文项目
同项目期刊论文
In vivo detection and imaging of low-density foreign body with microwave-induced thermoacoustic tomo
Photoacoustic molecular imaging with antibody-functionalized single-walled carbon nanotubes for earl
Functional single-walled carbon nanotubes based on an integrin alpha(v)beta(3) monoclonal antibody f
Survivin mediates self-protection through ROS/cdc25c/CDK1 signaling pathway during tumor cell apopto
mu-Calpain regulates caspase-dependent and apoptosis inducing factor-mediated caspase-independent ap
Preclinical photoacoustic imaging endoscope based on acousto-optic coaxial system using ring transdu
Quantitative measurement of reactive oxygen species in vivo by utilizing a novel method: chemilumine
Mitochondrial autophagy protects against heat shock-induced apoptosis through reducing cytosolic cyt
Increasing the Efficiency of Photodynamic Therapy by Improved Light Delivery and Oxygen Supply Using
Enhancement of chemotherapeutic agent-induced apoptosis by inhibition of NF-kappa B using ursolic ac
期刊信息
位置：