三维树枝状银薄膜的可控生长及其在表面增强拉曼光谱中的应用

通过电流置换反应制备了树枝状银纳米薄膜。在反应过程中通过控制反应时间和硝酸银的浓度,得到了不同形貌、分布和密度的树枝状银薄膜,从而得到了具有不同SERS性能的树枝状银纳米薄膜。选取了具有最佳SERS性能的树枝状银纳米薄膜对罗丹明6G进行了微量检测、再现性检测和稳定性检测,其检测限可达到1×10~(-11) mol·L~(-1),具有优良的再现性和良好的稳定性。     

二步电沉积法制备Au/氧化石墨烯复合薄膜作为SERS基底

采用二步电沉积方法在Ti片表面制备了Au-氧化石墨烯（Au-GO）复合薄膜,通过XRD、SEM、XPS等对薄膜的组成、结构和形貌进行了表征,并以罗丹明6G（R6G）为探针分子,对Au-GO/Ti基底的SERS活性进行了表征。结果显示,Au纳米颗粒尺寸约为60 nm,均匀、致密分布于GO表面,该基底显示出较高的SERS活性,对R6G分子的检测极限可达~10^-10 mol·L^-1,增强因子高达约10⁶,且基底显示出良好的稳定性,在冰箱中存放90 d后,SERS活性仅降低30%左右。     

二步电沉积法制备Au/氧化石墨烯复合薄膜作为SERS基底

采用二步电沉积方法在Ti片表面制备了Au-氧化石墨烯（Au-GO）复合薄膜,通过XRD、SEM、XPS等对薄膜的组成、结构和形貌进行了表征,并以罗丹明6G（R6G）为探针分子,对Au-GO/Ti基底的SERS活性进行了表征。结果显示,Au纳米颗粒尺寸约为60 nm,均匀、致密分布于GO表面,该基底显示出较高的SERS活性,对R6G分子的检测极限可达~10^-10 mol·L^-1,增强因子高达约10⁶,且基底显示出良好的稳定性,在冰箱中存放90 d后,SERS活性仅降低30%左右。     

锂离子电池负极Si@LiAlO2纳米复合材料的简易制备

采用溶剂热法和煅烧法制备了LiAlO₂包覆Si纳米颗粒（Si@LiAlO₂）的复合材料。Si@LiAlO₂纳米颗粒具有开口和通道的树枝状结构。电化学性能测试表明,其在100 mA·g^-1电流密度下循环100次后可逆容量为364.1 mAh·g^-1。纳米复合材料的树枝状结构使其具有优越的循环性能。在树枝状结构中,纳米尺度的硅颗粒缩短了锂离子的传输路径,LiAlO₂包覆层、孔隙和开口缓冲了硅在充放电过程中的体积变化。     

磁性Ag@Fe3O4@C负载纳米金的制备及其SERS性能

利用一步溶剂热法制备了具有核壳结构的Ag@Fe₃O₄磁性纳米颗粒,然后以葡萄糖作为碳源对Ag@Fe₃O₄进行包覆,再利用酰胺化反应成功的将聚乙烯亚胺（PEI）修饰到Ag@Fe₃O₄@C表面,最后以N-Au共价键的方式将Au纳米粒子组装到Ag@Fe₃O₄@C表面。以4-巯基苯甲酸（4MBA）为拉曼活性探针分子来考察该复合纳米材料的表面增强拉曼（SERS）性能。通过控制Au纳米粒子的加入量,来调节Ag@Fe₃O₄@C-Au复合纳米材料的SERS活性。通过实验测试及利用时域有限差分法（FDTD）得出不同纳米金用量包覆的Ag@Fe₃O₄@C磁性纳米颗粒对4MBA的SERS效果依次为Ag@Fe₃O₄@C-Au-40 > Ag@Fe₃O₄@C-Au-10 > Ag@Fe₃O₄@C-Au-60 > Ag@Fe₃O₄@C,其中Ag@Fe₃O₄@C-Au-40的饱和磁化强度为411 A·g^-1,其对4MBA的检测限为1×10^-9 mol·L^-1。这种功能性复合材料既具有良好的SERS活性,又可通过外加磁场的方式实现对待测分子的分离、富集。     

基于疏水滤纸的金纳米花SERS 基底高灵敏检测牛奶中的三聚氰胺

将海胆状金纳米花(gold nanoflowers, GNFs)疏水滤纸基底和表面增强拉曼散射(surface-enhanced Raman scattering, SERS)技术相结合,实现了牛奶中三聚氰胺的高灵敏检测。由左旋多巴还原制备的GNFs拥有许多尖锐突起和尖端可激发强局部电磁场增强(electromagnetic enhancement, EM),产生大量的“热点”,提高SERS检测的灵敏度。采用疏水滤纸作为衬底,改进了纸基衬底上纳米材料分布不均匀的缺点。进而评估了SERS基底的灵敏度、稳定性和重现性。通过对加标牛奶中三聚氰胺的定量检测,在1×10_-3^~1×10_-9 ^mol/L范围内,牛奶中三聚氰胺的浓度对数与SERS强度呈良好的线性关系,检测限低至43 pmol/L,远低于同类检测方法。并且本方法检测实际样品结果与液相色谱法检测结果对比无显著性差异(p>0.05)。GNFs疏水滤纸SERS基底具有高灵敏度、稳定性、重现性和实用性的优点,为牛奶等其他食品中三聚氰胺的定量检测提供了参考价值。     

碳纸负载碳酸氢镍纳米颗粒的无酶葡萄糖电化学传感器

通过一步水热法在碳纸上原位生长碳酸氢镍纳米颗粒,利用粉末X射线衍射和扫描电子显微镜对材料的结构及形貌进行表征,发现碳纸上负载纯相Ni （HCO₃）₂时具有较多的催化活性位点,利于葡萄糖的催化氧化反应进行。循环伏安法和时间-电流响应曲线表明该电极的检测限为0.98 μmol·L^-1,线性范围为2.95~1.02 mmol·L^-1,灵敏度为935 μA·L·mmol^-1·cm^-2,同时具有优异的选择性及稳定性。此外,该传感器能够实现对乳制品中葡萄糖的快速检测。这些结果表明,过渡金属和导电基底的协同作用会增强复合材料整体的导电性能和催化性能。     

双金属离子调控型镍钴氧化物纳米片用于非对称超级电容器

通过水热-煅烧两步法制备了系列镍钴氧化物（NCO）纳米片。通过改变前驱体溶液中的镍、钴离子物质的量之比,进而调控NCO纳米片中的过渡金属离子比例。NCO纳米片的晶相、形貌和结构利用X射线衍射、扫描电子显微镜和X射线光电子能谱表征。此外,对NCO纳米片的电化学性能进行测试。结果表明,NCO-2（Ni_1.95Co₁O_x）纳米片在0.5 A·g^-1电流密度下,比电容为1 096.88 F·g^-1,且经过5 000次循环后具有78.26%的循环稳定性。以NCO-2为正极、活性碳为负极构成的非对称超级电容器,在功率密度为576 W·kg^-1时,能量密度为57.70 Wh·kg^-1。     

基于Ni12P5纳米粒子的电化学传感器用于灵敏测定葡萄糖

通过改进的热溶剂胶体合成法制备了单分散的Ni₁₂P₅纳米粒子,并利用X射线衍射、透射电子显微镜、X射线光电子能谱、X射线能谱对Ni₁₂P₅纳米粒子的晶体结构、化学组成和形貌等进行了表征。基于单分散Ni₁₂P₅纳米粒子研制出的非酶葡萄糖传感器具有出色的性能,其快速响应时间小于3 s,检测范围广（0.002~4.2 mmol·L^-1）,灵敏度高达1 572 mA·L·mol^-1·cm^-2,检测限低至0.8 μmol·L^-1。此外,该传感器在用于人体血液中葡萄糖的实际检测中取得了满意的效果。     

双金属离子调控型镍钴氧化物纳米片用于非对称超级电容器

通过水热-煅烧两步法制备了系列镍钴氧化物(NCO)纳米片。通过改变前驱体溶液中的镍、钴离子物质的量之比，进而调控NCO纳米片中的过渡金属离子比例。NCO纳米片的晶相、形貌和结构利用X射线衍射、扫描电子显微镜和X射线光电子能谱表征。此外，对NCO纳米片的电化学性能进行测试。结果表明，NCO-2(Ni_1.95Co₁O_x)纳米片在0.5 A·g^-1电流密度下，比电容为1 096.88 F·g^-1，且经过5 000次循环后具有78.26%的循环稳定性。以NCO-2为正极、活性碳为负极构成的非对称超级电容器，在功率密度为576 W·kg^-1时，能量密度为57.70 Wh·kg^-1。     

Quantitative surface enhanced Raman scattering detection based on the "sandwich" structure substrate

A sandwich structured substrate was designed for quantitative molecular detection using surface enhanced Raman scattering (SERS), in which the probe molecule was sandwiched between silver nanoparticles (SNPs) and silver nanoarrays. The SNPs was prepared using Lee-Meisel method, and the silver nanoarrays was fabricated on porous anodic aluminum oxide (AAO) using electrodepositing method. The SERS studies show that the sandwich structured substrate exhibits good stability and reproducibility, and the detection sensitivity of Rhodamine 6G (R6G) and Melamine can respectively reach up to 10(-19) M and 10(-9) M, which is improved greatly as compared to other SERS substrates. The improved SERS sensitivity is closely associated with the stronger electromagnetic field enhancement, which stems from localized surface plasmon (LSP) coupling between the two silver nanostructures. Furthermore, the SERS intensity increased almost linearly as the mother concentration increased, which indicates that such a sandwich structure may be used as a good SERS substrate for quantitative analysis.     

Magnetron sputtering of silver nanowires using anodic aluminum oxide template: a new active substrate of surface enhanced Raman scattering and an investigation of its enhanced mechanism

A high quality anodic aluminum oxide (AAO) template with ordered apertures about 50-80 nm was fabricated by anodizing aluminum in electrolytes through a two-step method, and silver nanowires with diameters from 40nm to 70nm were prepared on this AAO template by magnetron sputtering. On the glass covered with silver nanowires, high quality surface enhanced Raman scattering (SERS) spectra of sudan II (C₁₈H₁₆N₂O) with enhancement factors of 10⁵ were obtained. And comparison of SERS spectra on silver nanowires with the SERS spectra of silver colloids indicates that main enhanced mode is lightning rod effect of nanorods on the Sudan II/silver nanowires system.     

Biomimetic preparation of core‐shell structured surface‐enhanced Raman scattering substrate with antifouling ability,good stability,and reliable quantitative capability

The fouling and stability are two most critical limiting factors for practical applications of surface‐enhanced Raman scattering (SERS)‐based microfluidic electrophoresis device. Herein, we present a novel biomimetic nanoengineering strategy to achieve a SERS substrate featuring antifouling ability, good stability, and reliable quantitative capability. Typically, by employing tea polyphenol as the reducing agent, the substrate made of silver core‐gold shell nanostructures in situ grown on silicon wafer surface is fabricated. The core‐shell nanostructures are further embedded with internal standard molecules. Remarkably, the fabricated substrate preserves distinct SERS effects, adaptable reproducibility, and reliable quantitative ability even if the substrate is incubated with 15% H₂O₂, 13% HNO₃, or 10⁸ CFU/mL bacteria, or suffered from 12‐day continuous vibration at 250 rpm/min in PBS buffer. As a proof‐of‐concept application, the DNA‐functionalized substrate is capable of precise quantification of Hg²⁺ with a limit of detection down to ca. 1 pM even in sewage water.     

有序Au/Ag纳米碗阵列的简易制备及其表面增强拉曼散射性能

通过湿法化学合成基于SiO₂胶体晶体的大面积有序Au/Ag纳米碗(Au/AgNB)阵列。首先,在玻璃基板上组装3D SiO₂胶体晶体作为模板。然后,以Au纳米颗粒(AuNP)为种子,通过原位生长法在SiO₂模板上沉积一层Au纳米壳(AuNS)。再通过HCHO还原Ag⁺成Ag⁰,进一步在AuNS表面沉积Ag纳米壳,形成Ag/Au双纳米壳(Ag/AuNS)阵列。最后通过丙烯酸酯改性双向取向聚丙烯(BOPP)膜方便地获得了单层有序反转Ag/AuNB阵列。这种有序Au/AgNB阵列具有更佳的表面增强拉曼散射(SERS)活性,其SERS分析增强因子(AEF)可达2.23×10⁷。     

A surface-enhanced Raman scattering method for detection of trace glutathione on the basis of immobilized silver nanoparticles and crystal violet probe

Unsatisfactory sensitivity and stability for molecules with low polarizability is still a problem limiting the practical applications of surface-enhanced Raman scattering (SERS) technique. By preparing immobilized silver nanoparticles (Fe₃O₄/Ag) through depositing silver on the surface of magnetite particles, a highly sensitive and selective SERS method for the detection of trace glutathione (GSH) was proposed on the basis of a system of Fe₃O₄/Ag nanoparticles and crystal violet (CV), in which the target GSH competed with the CV probe for the adsorption on the Fe₃O₄/Ag nanoparticles. Raman insensitive GSH replaced the highly Raman sensitive CV adsorbed on the surface of Fe₃O₄/Ag particles. This replacement led to a strong decrease of the CV SERS signal, which was used to determine the concentration of GSH. Under optimal conditions, a linear response was established between the intensity decrease of the CV SERS signal and the GSH concentration in the range of 50–700 nmol L⁻¹ with a detection limit of 40 nmol L⁻¹. The use of a Fe₃O₄/Ag substrate provided not only a great SERS enhancement but also a good stability, which guarantees the reproducibility of the proposed method. Its use for the determination of GSH in practical blood samples and cell extract yielded satisfactory results.     

柠檬酸辅助可控制备花状银粒子及其表面增强拉曼散射性能

以抗坏血酸为还原剂,柠檬酸为结构导向剂,一步还原硝酸银,合成了尺寸和形状可调的花状银颗粒。纳米粒子的粒径可在600～1 200 nm范围内调整,表面突起可达到10～25 nm。柠檬酸的化学性质在银纳米粒子合成多级花状银结构的过程中起着至关重要的作用。通过改变柠檬酸或抗坏血酸溶液的用量,银结构的各向异性形貌可以很容易地调节。以制备的多级花状银颗粒作为表面增强拉曼散射(SERS)基底,对浓度为10~(-10)mol·L~(-1)的罗丹明6G(R6G)仍具有较高的检测灵敏度。     

Dealloying Ag–Al Alloy to Prepare Nanoporous Silver as a Substrate for Surface‐Enhanced Raman Scattering: Effects of Structural Evolution and Surface Modification

Sensitive detection of molecules by using the surface‐enhanced Raman scattering (SERS) technique depends on the nanostructured metallic substrate and many efforts have been devoted to the preparation of SERS substrates with high sensitivity, stability, and reproducibility. Herein, we report on the fabrication of stable monolithic nanoporous silver (NPS) by chemical dealloying of Ag–Al precursor alloys with an emphasis on the effect of structural evolution on SERS signals. It was found that the dealloying conditions had great influence on the morphology (the ligament/pore size) and the crystallization status, which determined the SERS signal of rhodamine 6G on the NPS. NPS with small pores, low residual Al, and perfect crystallization gave high SERS signals. A high enhancement factor of 7.5×10⁵ was observed on bare NPS obtained by dealloying Ag₃₀Al₇₀ in 2.5 wt % HCl at room temperature followed by 15 min aging at around 85 °C. After coating Ag nanoparticles on the NPS surface, the enhancement factor increased to 1.6×10⁸ owing to strong near‐field coupling between the ligaments and nanoparticles.     

Facile synthesis of two-dimensional PA-Ag@C film for highly sensitive SERS detection

In this study, the surface of polyamide (PA) films are electrostatically deposited with the carbon-coated silver (Ag@C) nanoparticles, resulting in a two-dimensional (2D) PA-Ag@C film substrate. The TEM images demonstrate that the nanoparticles were successful synthesized. By adjusting the pH of the system, the core–shell structure and the 2D SERS substrate work together to improve the sensitivity, stability, and repeatability of the substrate to be used in complex real-world water samples. The SERS enhancement effect and substrate uniformity were determined using rhodamine 6G (R6G), crystal violet (CV), and malachite green (MG). The results indicate that the 2D PA-Ag@C film substrate in this study has the optimal Raman effect at a system pH of 6. Under ideal pH conditions, the R6G detection limit (LOD) is as low as 10⁻¹⁰ M (D2 attenuation), and the Raman signal intensity deviation of the same substrate is maintained within 9.49%. Overall, the Raman signal of probe molecule on the fabricated PA-Ag@C film possesses excellent sensitivity, repeatability, and stability.     

有序Au/Ag纳米碗阵列的简易制备及其表面增强拉曼散射性能

通过湿法化学合成基于SiO₂胶体晶体的大面积有序Au/Ag纳米碗(Au/AgNB)阵列。首先,在玻璃基板上以3D SiO₂胶体晶体作为模板。然后,在Au纳米颗粒(AuNP)种子的帮助下,通过原位生长方法在模板上沉积一层Au纳米壳(AuNS)。再通过HCHO还原Ag⁺使AuNS表面进一步沉积Ag纳米壳,形成Ag/Au双纳米壳(Ag/AuNS)阵列。通过丙烯酸酯改性双向取向聚丙烯(BOPP)方便地获得了单层有序反转Ag/AuNB阵列。这种有序Au/AgNB阵列具有更佳的表面增强拉曼散射(SERS)活性,其SERS分析增强因子(AEF)可达2.23×10⁷。