SERS Study of Apo-Metallothionein Adsorbed on Roughened Gold Surfaces

利用表面增强拉曼光谱(SERS)技术研究了金属硫蛋白(MT)与脱金属硫蛋白(apo-MT)在粗糙金表面的吸附行为。结果表明:MT通过氨基与金作用;apo-MT与金的作用位点受制备方法影响:在溶液中预制的apo-MT通过半胱氨酸残基的巯基与金结合,在金表面制备的apo-MT通过氨基和巯基与金结合。SERS更适合于研究MT的结构特征。The adsorption of metallothionein and apo-metallothionein on roughened Au surfaces was studied by SERS technique.The results indicate that MT is adsorbed via-NH2 group on roughened gold surfaces.The adsorption site of apo-MT on Au is determined by the preparation method of apo-MT.The apo-MT prepared in solution is adsorbed via the-SH group on Au whereas that prepared on the Au surface is adsorbed via-SH and-NH2.国家自然科学基金(20503040,20773165);; 973计划(2007CB935603);; 厦门大学固体表面物理化学国家重点实验室开放课题项目资

软光刻法制备具有表面微结构的角蛋白膜

近年来,使用微纳米制造工艺将蛋白质或多肽进行高精度空间图案化,推动了细胞生物学、组织工程学、药物科学等领域的发展.同时,羊毛角蛋白作为一种储量大的天然生物蛋白质,具有优异的水溶性、良好的生物相容性和可控的降解性,但羊毛角蛋白通常不能自组装形成凝胶网络或其他不溶形式,因此,使用羊毛角蛋白制备如纤维、薄膜、凝胶等的成型结构存在很大困难.本工作通过使用化学修饰的方法,在角蛋白上接枝功能基团,使角蛋白获得光敏感性,探究了共价交联法制备具有表面微结构角蛋白膜的可行性.并用3D激光扫描显微镜、紫外可见近红外光谱仪和傅里叶变换显微红外光谱仪对薄膜结构进行了表征.结果表明,使用软光刻法可以得到表面微结构完整度很高的角蛋白膜.本工作对羊毛角蛋白共价交联法进行了实验探索,实验结果不仅为人们提供了一种软光刻技术制备具有表面微结构的角蛋白膜的方法,而且为羊毛角蛋白制备成型结构提供了新的途径.国家自然科学基金(Nos.21771150,21401154,U1405226)111计划(No.B16029)广东省自然科学基金(No.2014A030310005)中央高校基本业务费(No.20720170011)资助~

粗糙铂电极上甲酸吸附氧化的电化学原位表面增强拉曼光谱研究

采用循环伏安法和电化学原位表面增强拉曼光谱 (SERS)技术研究甲酸的解离吸附与氧化行为 .首次报道了甲酸吸附、解离和氧化的电化学原位SERS谱 ,发现甲酸在粗糙铂电极上能自发解离吸附 ;首次成功地获得了粗糙铂电极上甲酸吸附解离的强吸附中间体CO和活性中间体COOH的表面增强拉曼光谱 ,同时首次检测到甲酸氧化最终产物CO2 的拉曼光谱信号 ,从分子水平证实甲酸解离吸附反应的双途径机理

Reaction of p-Chloronitrobenzene Adsorbed on Silver Nanoparticles

Corresponding author. Email: [email protected]; Tel: +86-592-2189023[中文文摘]表面增强拉曼光谱(SERS)具有极高的检测灵敏度,通过检测吸附分子的SERS信号,可以获得表面吸附分子的结构以及可能发生的反应.在拉曼激发光源的辐射下,在碱性溶液中,银纳米粒子表面吸附的对氯硝基苯(PCNB)的SERS光谱与其固体的常规拉曼光谱相比,出现异常SERS谱.通过采用密度泛函理论(DFT)计算,对PCNB以及可能的偶联产物p,p′-二氯偶氮苯(DCAB)进行理论分析以及谱峰归属,发现这些异常峰来自其偶联产物DCAB的偶氮C-N=N-C基团的基频振动. [英文文摘]Surface-enhanced Raman spectroscopy (SERS) on silver nanoparticles is highly sensitive because of surface plasmon resonance. We have studied the structures and photoinduced chemical reactions of p-chloronitrobenzene (PCNB) molecules adsorbed on silver nanoparticles using a combination of SERS and density functional theory (DFT) calculations. When the PCNB molecules are adsorbed to the surface of silver nanoparticles in alkaline solution, the SERS spectra are very different from the normal Raman spectra of PCNB. Comparison of the DFT simulated Raman spectra of PCNB and p,p-dichloroazobenzene (DCAB) indicates that the new peaks in the SERS spectrum of PCNB adsorbed on silver nanoparticles arise from the azo (C－N＝N－C) group of DCAB.国家自然科学基金(20973143, 91027009, 21021002);国家重点基础研究发展规划项目(973)(2009CB930703);厦门大学(2010121020

In-situ SERS study on the electro-oxidation with HCOOH on a roughened platinum electrode

The dissociative adsorption and oxidation behavior of HCOOH on Pt was investigated by cyclic voltammogram (CV) and in-situ surface enhanced Raman spectroscopy (SERS) techniques. The in-stiu SERS of HCOOH adsorption, dissociation and oxidation on rough Pt is reported. It is found that HCOOH can spontaneously dissociate. The surface Raman spectra of CO, the strongly adsorbed intermediate and COOH, the weakly adsorbed intermediate of the dissociative adsorption of HCOOH were successfully obtained for the first time. At the same time, the Raman spectra of the finally oxidized product CO2 of HCOOH was also firstly detected. The dual path reaction mechanism for the oxidation of HCOOH was confirmed at molecular level

基于内容的自适应量化数字音频盲水印算法

现有量化调制音频水印技术普遍采纳了均匀量化策略,其不仅需要结合大量实验确定量化步长,而且难以保证不可感知性与鲁棒性的良好平衡.以模糊聚类分析理论为基础,提出了一种自适应量化小波域数字音频盲水印算法.该算法能够结合数字音频局部特征,利用模糊聚类分析自适应确定量化步长,并在小波域内将水印信号嵌入到音频数据段的低频分量中.仿真实验表明,所提出的算法不仅具有较好的不可感知性,而且对于叠加噪声、重新采样、重新量化、低通滤波、MP3压缩等音频处理与攻击均具有较好的鲁棒性

Study on impact resistance of bionic interlocking brick-mud structures

The exquisite meso- or micro-structures of natural biomaterials, e.g., brick-mud microstructures of nacre and conch shell, gradient micro-structures of bamboo and antlers, and interlocking meso-structures of beetle shells, can enhance the ability of materials to resist external impact from different aspects. This will provide inspiration for the design, optimization and performance improvement of new bionic impact resistance structures. In this paper, gradient and interlocking structures are introduced into brick-mud structures, and then gradient interlocking and bidirectional interlocking brick-mud structures are designed, and finally samples are prepared by 3D printing technology. The results of pendulum impact experiment show that the larger the cell size gradient, the higher the energy absorption of the gradient interlocking brick-mud structure, and that the smaller the number of elliptical units in the interlocking area in the cell, the higher the energy absorption of the bidirectional interlocking brick-mud structure. The amounts of energy absorbed by the two proposed interlocking brick-mud structures during impact can be up to 6.2 times and 2.5 times that by the uniform nacre brick-mud structure, respectively. The mechanism of the energy absorption improvement of the interlocking structure is studied by using the finite element method. The gradient interlocking design can significantly improve the stress distribution and deformation coordination in the impact area, and increase the stress level and bending deformation in the sample before failure. Moreover, the bidirectional interlocking design can increase the number and deflection of cracks in the fracture area, and further extend the crack propagation path, thus improving energy dissipation