化学沉镍金速率分析与应用

通过试验分析,得出了温度、pH、浓度与化学镍、化学金析出速率的关系,为精确控制化学镍、化学金的镀层厚度、降低化金成本提供了依据。     

基于介电泳机理的金纳米颗粒传感器装配方法

研究了一种基于介电泳机理的金纳米颗粒传感器装配方法。在分析介电泳工作原理的基础上,利用Comsol Multiphysics仿真软件,对平面微电极条件下所产生的空间电场进行了建模仿真,研究了金纳米粒子极化模型及相关介电泳频谱特性。设计加工了基于光刻标准工艺和引线键合技术的平面微电极阵列,构建了具有三维位移平台和视频监控装置的介电泳装配实验平台。以250nm金颗粒为实验对象,在理论分析基础上,完成了在微电极阵列上的介电泳组装实验研究,并通过电特性测量验证了组装结果。实验结果表明:金纳米颗粒的介电泳组装效果与介质溶液的电导率、电场频率和幅度、金纳米粒子浓度、电极间隙及作用时间有关,在适宜的条件下,采用介电泳技术可实现对金纳米颗粒的有效操控和纳米器件装配,该方法为纳米传感器的制造提供了一种有效途径。     

毫米波射频互连微组装工艺优化研究

在毫米波产品的装配中,射频互连微组装工艺是影响产品性能的一个重要因素。采用三维电磁仿真软件对毫米波频段的组装缝隙宽度、金丝热超声楔焊跨距及拱高进行了建模仿真,分析了上述因素对驻波的影响。针对模拟仿真优化结果,给出了毫米波射频互连装配精度控制、接地焊接效果优化、金丝热超声楔焊线型及键合参数优化等相应的工艺优化措施,从而达到毫米波射频互连微组装工艺优化的目的。     

Gold Nanoshell Nanomicelles for Potential Magnetic Resonance Imaging,Light‐Triggered Drug Release,and Photothermal Therapy

A novel multifunctional drug‐delivery platform is developed based on cholesteryl succinyl silane (CSS) nanomicelles loaded with doxorubicin, Fe₃O₄ magnetic nanoparticles, and gold nanoshells (CDF‐Au‐shell nanomicelles) to combine magnetic resonance (MR) imaging, magnetic‐targeted drug delivery, light‐triggered drug release, and photothermal therapy. The nanomicelles show improved drug‐encapsulation efficiency and loading level, and a good response to magnetic fields, even after the formation of the gold nanoshell. An enhancement for T₂‐weighted MR imaging is observed for the CDF‐Au‐shell nanomicelles. These nanomicelles display surface plasmon absorbance in the near‐infrared (NIR) region, thus exhibiting an NIR (808 nm)‐induced temperature elevation and an NIR light‐triggered and stepwise release behavior of doxorubicin due to the unique characteristics of the CSS nanomicelles. Photothermal cytotoxicity in vitro confirms that the CDF‐Au‐shell nanomicelles cause cell death through photothermal effects only under NIR laser irradiation. Cancer cells incubated with CDF‐Au‐shell nanomicelles show a significant decrease in cell viability only in the presence of both NIR irradiation and a magnetic field, which is attributed to the synergetic effects of the magnetic‐field‐guided drug delivery and the photothermal therapy. Therefore, such multicomponent nanomicelles can be developed as a smart and promising nanosystem that integrates multiple capabilities for effective cancer diagnosis and therapy.     

Confinement of gold quantum dot arrays inside ordered mesoporous silica thin film

Periodic disposed quantum dot arrays are very useful for the large scale integration of single electron devices. Gold quantum dot arrays were self-assembled inside pore channels of ordered amino-functionalized mesoporous silica thin films, employing the neutralization reaction between chloroauric acid and amino groups. The diameters of quantum dots are controlled via changing the aperture of pore channels from 2.3 to 8.3 nm, which are characterized by HRTEM, SEM and FT-IR. UV-vis absorption spectra of gold nanoparticle/mesoporous silica composite thin films exhibit a blue shift and intensity drop of the absorption peak as the aperture of mesopores decreases,which represents the energy level change of quantum dot arrays due to the quantum size effect.     

Improved Hydrogen Production of Au–Pt–CdS Hetero‐Nanostructures by Efficient Plasmon‐Induced Multipathway Electron Transfer

The design of new functional materials with excellent hydrogen production activity under visible‐light irradiation has critical significance for solving the energy crisis. A well‐controlled synthesis strategy is developed to prepare an Au–Pt–CdS hetero‐nanostructure, in which each component of Au, Pt, and CdS has direct contact with the other two materials; Pt is on the tips and a CdS layer along the sides of an Au nanotriangle (NT), which exhibits excellent photocatalytic activity for hydrogen production under light irradiation (λ > 420 nm). The sequential growth and surfactant‐dependent deposition produce the three‐component Au–Pt–CdS hybrids with the Au NT acting as core while Pt and CdS serve as a co‐shell. Due to the presence of the Au NT cores, the Au–Pt–CdS nanostructures possess highly enhanced light‐harvesting and strong local‐electric‐field enhancement. Moreover, the intimate and multi‐interface contact generates multiple electron‐transfer pathways (Au to CdS, CdS to Pt and Au to Pt) which guide photoexcited electrons to the co‐catalyst Pt for an efficient hydrogen reduction reaction. By evaluating the hydrogen production rate when aqueous Na₂SO₃–Na₂S solution is used as sacrificial agent, the Au–Pt–CdS hybrid exhibits excellent photocatalytic activity that is about 2.5 and 1.4 times larger than those of CdS/Pt and Au@CdS/Pt, respectively.     

A Universal Platform for Macromolecular Deliveryinto Cells Using Gold Nanoparticle Layers via the Photoporation Effect

Although promising, it is challenging to develop a simple and universal method for the high‐efficiency delivery of biomacromolecules into diverse cells. Here, a universal delivery platform based on gold nanoparticle layer (GNPL) surfaces is proposed. Upon laser irradiation, GNPL surfaces show such good photothermal properties that absorption of the laser energy causes a rapid increase in surface temperature, leading to enhanced membrane permeability of the cultured cells and the diffusion of macromolecules into the cytosol from the surrounding medium. The high‐efficiency delivery of different macromolecules such as dextran and plasmid DNA into different cell types is achieved, including hard‐to‐transfect mouse embryonic fibroblasts (mEFs) and human umbilical vein endothelial cells (HUVECs), while cell viability is well maintained under optimized irradiation conditions. The platform vastly outperforms the leading commercial reagent, Lipofectamine 2000, especially in transfecting hard‐to‐transfect cell lines (plasmid transfection efficiency: ≈53% vs ≈19% for mEFs and ≈44% vs ≈8% for HUVECs). Importantly, as the gold nanoparticles (GNPs) constituting the GNPL are firmly immobilized together, the potential cytotoxicity caused by endocytosis of GNPs is effectively avoided. This platform is reliable, efficient, and cost‐effective with high‐throughput and broad applicability across different cell types, opening up an innovative avenue for high‐efficiency intracellular delivery.     

新图像匹配算法在金丝球引线键合机中的应用

随着当今社会对金丝球引线键合机的工作速度、定位精度要求的不断提高,对图像控制系统也提出了更高的要求.针对单纯使用MIL图像处理库提供的模板匹配算法会出现误判现象,提出了一种"二次梯形分层搜索的序贯相关判决算法"作为MIL匹配算法的补充,即对一幅图像实施一主一辅进行两次模板匹配运算的方法,使图像的匹配既能实现快速准确又不出现芯片误判的情况.目前该算法已在VC++中编程实现,并在工业上得到应用,结果表明此算法是高效可靠的.     

Selective Pd Deposition on Au Nanobipyramids and Pd Site‐Dependent Plasmonic Photocatalytic Activity

The synthesis of anisotropic metal nanostructures is strongly desired for exploring plasmon‐enabled applications. Herein, the preparation of anisotropic Au/SiO₂ and Au/SiO₂/Pd nanostructures is realized through selective silica coating on Au nanobipyramids. For silica coating at the ends of Au nanobipyramids, the amount of coated silica and the overall shape of the coated nanostructures exhibit a bell‐shaped dependence on the cationic surfactant concentration. For both end and side silica coating on Au nanobipyramids, the size of the silica component can be varied by changing the silica precursor amount. Silica can also be selectively deposited on the corners or facets of Au nanocubes, suggesting the generality of this method. The blockage of the predeposited silica component on Au nanobipyramids enables further selective Pd deposition. Suzuki coupling reactions carried out with the different bimetallic nanostructures functioning as plasmonic photocatalysts indicate that the plasmonic photocatalytic activity is dependent on the site of Pd nanoparticles on Au nanobipyramids. Taken together, these results suggest that plasmonic hot spots play an important role in hot‐electron‐driven plasmonic photocatalysis. This study opens up a promising route to the construction of anisotropic bimetallic nanostructures as well as to the design of bimetallic plasmonic‐catalytic nanostructures as efficient plasmonic photocatalysts.     

纳米金棒诱导A549细胞产生自噬的机制研究

纳米金棒(AuNRs)具有众多独特的属性,已广泛运用于生物医学领域,但其是否具有潜在的生物危害尚有争议.作者运用了激光扫描共聚焦显微镜技术、western blotting技术和其他分子生物学方法从细胞氧化应激的角度探讨了AuNRs诱导A549细胞产生自噬的分子机制.研究结果表明,4μg·mL-1的AuNRs处理6 h能够诱导A549细胞自噬标志蛋白LC3-Ⅱ表达增加,LC3蛋白从细胞核转移至细胞质并形成自噬小泡.进一步研究发现,AuNRs能够降低A549细胞线粒体膜电位、ATP含量、UCP2蛋白表达水平以及细胞抗氧化能力并导致活性氧蓄积,后者可能最终引起细胞产生自噬.而10 mmol·L-1抗氧化剂NAC能够逆转上述线粒体及细胞功能的改变,并抑制自噬的发生.这一研究为深入认识其生物危害及可能机制提供了有力的实验证据.