Properties of Magnetic Nanoparticles about Doped Rare Earth and Its Composites

The magnetic liquid was prepared with ferric salt by inorganic gel technology. The effect of the doped rare earth elements on the properties of magnetic particles was analyzed. The magnetic liquid was composed with clay mineral into magnetic mineral composites. The crystal structure and micro-morphology of the nanoparticles were studied by XRD and TEM. The results show that the crystal structure of the magnetic particles doped 0.5 % of lanthanum is more complete, and the magnetic response capability is higher with doping agent. At the same time, the possibility of the clay mineral magnetic composites as the carrier of target drug was probed.     

紫杉醇硅胶表面分子印迹纳米颗粒的制备

以紫杉醇为模板分子,紫杉醇上的羟基与异氰酸酯丙基三乙氧基硅烷(IPTS)反应形成共价复合物,然后和交联剂正硅酸乙酯(TEOS)通过溶胶-凝胶的方法涂覆在纳米硅胶表面上,以热裂解的方式去除模板分子后形成紫杉醇硅胶表面分子印迹纳米颗粒。通过吸附实验分析研究了紫杉醇硅胶表面分子印迹纳米颗粒的亲和性能,结果表明印迹纳米颗粒对紫杉醇有良好的亲和性。     

金纳米颗粒制备及其光学特性研究

采用晶种生长法通过改变晶种对生长溶液的体积比例、引入离子合成了棒状和星形金纳米颗粒.首先用NaBH4作为还原剂制得小粒径球形金纳米颗粒作为晶种溶液,生长溶液中引入AgNO3为辅助试剂、溴化十六烷三甲基铵(CTAB)为表面活性剂来引导合成形貌不同的颗粒.对制备的球状、棒状和星状金纳米颗粒进行了紫外-可见光谱测试和表面增强...     

利用SPR生物传感器检测缺血修饰白蛋白

缺血修饰白蛋白(IMA)的检测对心肌缺血的早期诊断和治疗具有重要意义。利用纳米金颗粒和混合巯基自组装于金膜表面上,研制了一种快速检测IMA的表面等离子体共振(SPR)生物传感器。同时比较了直接法和抑制法的检测下限。结果表明:直接检测法可以检测到393ng/L的IMA,而抑制检测法检测限小于5.0 ng/L。与现有的IMA检测方法相比,SPR生物传感器具有特异性好、检测下限低以及检测耗时短等优点。     

Myoglobin/gold nanoparticles/carbon spheres 3-D architecture for the fabrication of a novel biosensor

A novel biosensor based on a myoglobin/gold nanoparticles/carbon spheres (Mb-AuNPs-CNs) 3-D architecture bioconjunction has been fabricated for the determination of hydrogen peroxide (H₂O₂). Cyclic voltammetry (CV), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) were used to characterize the bioconjunction of the AuNPs-CNs with Mb. Experimental results demonstrate that the AuNPs-CNs hybrid material is more effective in facilitating electron transfer of the immobilized enzyme than CNs alone, which can be attributed to the unique nanostructure and larger surface area of the bioconjunction. The biosensor displayed good performance for the detection of H₂O₂ with a wide linear range from 0.28 μmol/L to 116.5 μmol/L and a detection limit of 0.12 μmol/L. The Michaelis-Menten constant K _M^app value was estimated to be 0.3 mmol/L. The resulting biosensor exhibited fast amperometric response, and good stability, reproducibility, and selectivity to H₂O₂. This article is published with open access at Springerlink.com     

Photoluminescence and doping mechanism of theranostic Eu3+/Fe3+ dual-doped hydroxyapatite nanoparticles

Theranostic nanoparticles currently have been regarded as an emerging concept of ‘personalized medicine’ with diagnostic and therapeutic dual-functions. Eu³⁺ doped hydroxyapatite (HAp) has been regarded as a promising fluorescent probe for in vivo imaging applications. Additionally, substitution of Ca²⁺ with Fe³⁺ in HAp crystal may endow the capability of producing heat upon exposure to a magnetic field. Here we report a preliminary study of doping mechanism and photoluminescence of Eu³⁺ and Fe³⁺ doped HAp nanoparticles (Eu/Fe:HAp). HAp with varied concentration of Eu³⁺ and Fe³⁺ doping are presented as Eu(10 mol%):HAp, Eu(7 mol%)-Fe(3 mol%):HAp, Eu(5 mol%)-Fe(5 mol%):HAp, Eu(3 mol%)-Fe(7 mol%):HAp, and Fe(10 mol%):HAp in the study. The results showed that the HAp particles, in nano-size with rod-like morphology, were successfully doped with Eu³⁺ and Fe³⁺, and the particles can be well suspended in cell culture medium. Photoluminescence analysis revealed that particles have prominent emissions at 536 nm, 590 nm, 615 nm, 650 nm and 695 nm upon excitation at a wavelength of 397 nm. Moreover, these Eu/Fe:HAp nanoparticles belonged to B-type carbonated HAp, which has been considered an effective biodegradable and biocompatible drug/gene carrier in biological applications.     

Structural Insights into Iron Ions Accumulation in Dps Nanocage

Dps (DNA-binding protein from starved cells) is well known for the structural protection of bacterial DNA by the formation of highly ordered intracellular assemblies under stress conditions. Moreover, this ferritin-like protein can perform fast oxidation of ferrous ions and subsequently accumulate clusters of ferric ions in its nanocages, thus providing the bacterium with physical and chemical protection. Here, cryo-electron microscopy was used to study the accumulation of iron ions in the nanocage of a Dps protein from Escherichia coli. We demonstrate that Fe²⁺ concentration in the solution and incubation time have an insignificant effect on the volume and the morphology of iron minerals formed in Dps nanocages. However, an increase in the Fe²⁺ level leads to an increase in the proportion of larger clusters and the clusters themselves are composed of discrete ~1–1.5 nm subunits.     

纳米银抗菌材料研发现状

介绍了纳米银抗菌材料的研究与开发现状 ,并叙述了纳米银的制备及其应用     

用磁控溅射法制备的Ag-MgF2的复合薄膜的研究

采用RF磁控溅射方法制备了Ag-MgF2复合薄膜.通过XRD测量,发现当退火温度在300～500℃时,Ag以晶态形式镶嵌在非晶态介质中;当退火温度低于300℃时候,Ag以非晶态形式存在.在分层镀Ag和MgF2薄膜后,经过热处理使Ag颗粒扩散在MgF2介质中,通过AFM观察,对复合薄膜形貌进行了分析:如果先镀MgF2薄膜,再镀Ag薄膜,发现Ag颗粒主要分布在薄膜的表面,并且富集形成较大的颗粒,表现出块体Ag的吸收特性.而先镀Ag薄膜,然后再镀MgF2薄膜,经过热处理,可以形成Ag颗粒均匀镶嵌在介质中形成的复合薄膜.同时对样品的吸收特性也进行了研究.