负载姜黄素的氧化锌纳米粒的制备及抗癌评价

氧化锌纳米粒(ZnO NPs)的化学稳定性、生物相容性和高载药性能使其有望成为一种新型药物传递载体.研究拟开发一种经N-乙酰-L-半胱氨酸(NAC)封端并表面功能化的ZnO NPs,作为抗癌药物姜黄素的给药系统.在含NAC的溶液中,用ZnCl2和NaOH成功制备NAC封端ZnO NPs(ZnO-NAC NPs),然后将姜黄素共价结合到纳米粒表面,制得载药纳米粒(ZnO-NAC-Cur NPs).用X射线衍射法、傅里叶变换红外光谱法、透射电镜、扫描电镜(SEM)和动态光散射法进行表征.结果表明,ZnO-NAC-Cur NPs呈近球形,均匀分散,平均粒径约为70 nm. ZnO-NAC-Cur NPs几乎无溶血性.此外,用B16F10鼠黑色素瘤细胞进行MTT细胞毒试验,结果表明,IC50值从17.23μg·mL-1(游离姜黄素)降到8.78μg·mL-1(ZnO-NAC-Cur NPs).该结果表明,载药纳米粒的抗癌活性增强.

Box-Behnken响应面法优化姜黄素氧化锌纳米粒的制备工艺

目的优化姜黄素氧化锌纳米粒(ZnO-Curcumin nanoparticles,ZnO-Cur NPs)的制备工艺。方法利用姜黄素分子上的基团可以与氧化锌纳米粒(ZnO nanoparticles,ZnO NPs)表面的羟基形成氢键及配位键,来制备ZnO-Cur NPs,通过单因素考察后,以载药量为指标,以制备温度、pH、空白ZnO NPs与姜黄素的投料比为响应因子,采用Box-Behnken响应面法优化ZnO-Cur NPs的制备工艺。结果ZnO-Cur NPs的优化制备工艺为温度90.3℃,pH=8.93,ZnO NPs与姜黄素的投料比为1∶2。在此工艺条件下制备的ZnO NPs载药量可达29.33%,与预测值30.15%的相对误差为0.60%。结论优化所得ZnO-Cur NPs制备工艺稳定、可行,适用于该制剂的制备,同时也说明建立的回归模型合理。

High Performance Ultraviolet Photodetector Fabricated with ZnO Nanoparticles-graphene Hybrid Structures

Ultraviolet （UV） photodetector constructed by ZnO material has attracted intense research and commercial interest. However, its photoresistivity and photoresonse are still unsatisfied. Herein, we report a novel method to assemble ZnO nanoparticles （NPs） onto the reduced graphite oxide （RGO） sheet by simple hydrothermal process without any surfactant. It is found that the high-quality crystallized ZnO NPs with the average diameter of 5 nm are well dispersed on the RGO surface, and the density of ZnO NPs can be readily controlled by the concentration of the precursor. The photodetector fabricated with this ZnO NPs- RGO hybrid structure demonstrates an excellent photoresponse for the UV irradiation. The results make this hybrid especially suitable as a novel material for the design and fabrication of high performance UV photodector.

Light-induced ZnO/Ag/rGO bactericidal photocatalyst with synergistic effect of sustained release of silver ions and enhanced reactive oxygen species

Silver nanoparticles (Ag NPs) can effectively address the issue of antibiotic-resistant bacterial infections to reduce the potential toxicity of Ag NPs. Although challenging, it is, therefore, necessary to achieve the sustainable release of Ag+ ions from a finite amount of Ag NPs. This study aims at designing an efficient and benign antimicrobial silver-based ternary composite composed of photocatalysis zinc oxide (ZnO) and reduced graphene oxide (rGO) as a carrier, in which the reactive oxygen species (ROS) excited from ZnO and Ag+ ions released from the Ag NPs cooperate to realize an effective antibacterial activity against E. coli and S. aureus. The constant effective bacterial performance of the ternary photocatalyst with minimum Ag content can be attributed to the increase in the available quantity of ROS, which results from the enhanced separation efficiency of the photogenerated carriers. The proposed system notably realized the long-term sustainable release of Ag+ ions with low concentration for 30 days when compared with an equivalent amount of silver nitrate. Moreover, the use of the composite prevents biotoxicity and silver wastage, and imparts enhanced stability to the long-lasting antibacterial efficacy.

Highly Ordered Lattice Orientation of ZnO Nanoparticles Formed in Confined Space

Oriented aggregation of nanoparticles has been accomplished by means of solid state reac- tion. Non-crystallized and crystallized ZnO nanoparticles/clusters could be accommodated in the lamellar spacing of inorganic-organic composite, which were prepared by thermolysis of layered solid zinc-oleate complex at 260 and 300 ℃ in air, respectively. High-resolution transmission electron microscopy and selected area electron diffraction patterns indicate that aggregates are single crystals with various defects. The photoluminescence excitation spectra of both samples show two bands at 272 and 366 nm. The former may originate from electron transfer from valence band to conduction band in ZnO clusters composed of less than 200 ZnO molecules （2R〈2 nm）.

Large scale synthesis of ZnO nanoparticles via homogeneous precipitation

In order to synthesize ZnO nanoparticles economically, industrial-grade zinc sulfate and urea were utilized to synthesize ZnO precursors in a stirred-tank reactor or a Teflon-lined autoclave at 100-180 ℃ under complete sealing condition. The ZnO precursors were calcined at 450 ℃ for 3 h to, synthesize ZnO nanoparticles. The composition of the precursors and the formation mechanism of ZnO were studied by thermogravimetric analysis and Fourier transform infrared spectroscopy. The results of X-ray diffraction, transmission electron microscopy and scanning electron microscopy of the ZnO powders demonstrate that high-purity zincite ZnO nanoparticles are synthesized. Orthogonal experiments were performed to find out the optimal conditions for the maximum yield and the minimum size. The ettect of temperature on the size ofZnO nanoparticles was investigated. The results show that a higher temperature is propitious to obtain smaller nanoparticles.

High-performance flexible and broadband photodetectors based on PbS quantum dots/ZnO nanoparticles heterostructure

Flexible and broadband photodetectors have drawn extensive attention due to their potential application in foldable displays, optical communications, environmental monitoring, etc. In this work, a flexible photodetector based on the crystalline PbS quantum dots(QDs)/ZnO nanoparticles(NPs) heterostructure was proposed. The photodetector exhibits a broadband response from ultraviolet-visible(UV-Vis)to near infrared detector(NIR) range with a remarkable current on/off ratio of 7.08×10^3under 375 nm light illumination.Compared with pure ZnO NPs, the heterostructure photodetector shows the three orders of magnitude higher responsivity in Vis and NIR range, and maintains its performance in the UV range simultaneously. The photodetector demonstrates a high responsivity and detectivity of4.54 A W-1and 3.98×10^12Jones. In addition, the flexible photodetectors exhibit excellent durability and stability even after hundreds of times bending. This work paves a promising way for constructing next-generation high-performance flexible and broadband optoelectronic devices.

Preparation and characterization of zinc oxide nanoparticles

In the present study, the zinc oxide nanoparticles(ZnO NPs) were prepared by using a sol-gel method. The characterization of ZnO NPs, such as particle size, morphology, crystal form, optical properties and p H-responsive behavior, was carried out. The in vitro anti-tumor activity of ZnO NPs was evaluated on PC-3M and 4T1 cell lines. The results indicated that ZnO NPs were spherical NPs with uniform particle size, excellent fluorescence properties, and p H-responsive behavior. The in vitro anti-tumor activity of ZnO NPs was observed on PC-3M and 4T1 cell lines. Considering to above characteristics, Zn O NPs could be used as drug delivery carries for loading active compound performing therapeutic and diagnostic effect.

ZnO nanopowders and their excellent solar light/UV photocatalytic activity on degradation of dye in wastewater

Low-cost and scalable preparation,high photocatalytic activity,and convenient recycle of Zn O nanopowders(NPs)would determine their practical application in purifying wastewater.In this contribution,ZnO NPs were scalably synthesized via the simple reaction of Zn powder with H_2O vapor in autoclave.The structural,morphological and optical properties of the samples were systematically characterized by X-ray diffraction,scanning electron microscopy,Fourier transform infrared spectra,transmission electron microscopy,Micro-Raman,photoluminescence,and ultraviolet-visible spectroscopy.The as-prepared Zn O NPs are composed of nanoparticles with 100–150 nm in diameter,and have a small Brunauer-Emmett-Teller surface area of 6.85 m^2/g.The formation of Zn O nanoparticles is relative to the peeling of H_2 release.Furthermore,the product has big strain-stress leading to the red-shift in the band gap of product,and shows a strong green emission centered at 515 nm revealing enough atomic defects in Zn O NPs.As a comparison with P25,the obtained dust gray Zn O NPs have a strong absorbance in the region of 200–700 nm,suggesting the wide wave-band utilization in sunlight.Based on the traits above,the Zn O NPs show excellent photocatalytic activity on the degradation of rhodamine B(Rh-B)under solar light irradiation,close to that under UV irradiation.Importantly,the Zn O NPs could be well recycled in water due to the quick sedimentation in themselves in solution.The low-cost and scalable preparation,high photocatalytic activity,and convenient recycle of Zn O NPs endow themselves with promising application in purifying wastewater.

Gold nanoparticle/ZnO nanorod hybrids for enhanced reactive oxygen species generation and photodynamic therapy

Gold nanoparticle （Au NP）@ZnO nanorod （NR） （Au@ZnO） hybrids with various ZnO：Au molar ratios were developed to enhance the generation of reactive oxygen species （ROS） in photodynamic therapy （PDT） applications. Introducing a metal/semiconductor heterostructure interface between Au NPs and ZnO NRs modulated electron transfer under ultraviolet （UV） irradiation, which dramatically suppressed the electron-hole recombination in ZnO and simultaneously increased the amount of excited electrons with high energy at Au NP surfaces. Hence, the ROS yield of the nanohybrid was considerably improved over those of pristine Au NPs or ZnO NRs alone and demonstrated a ＂1 ＋ 1 〉 2 effect.＂ This enhancement was strengthened with increases in the proportion of Au in the hybrid. The results showed that the Au@ZnO nanohybrids with a ZnO：Au ratio of 20：1 generated the highest ROS yield because they had the largest interface area between Au and ZnO, which in turn led to the lowest cell viability for HeLa and C2C12 cells during PDT. Furthermore, both ROS generation and cell destruction were positively correlated with nanohybrid dosage. The Au@ZnO hybrid （20：1, 100 μg/mL） resulted in HeLa cell viability as low as 28% after UV exposure for 2 min, which indicated its promising potential to improve the therapeutic efficacy of PDT.

Enhanced antibacterial activity of silica nanorattles with ZnO combination nanoparticles against methicillin-resistant Staphylococcus aureus

Silica nanorattles(SNs) with zinc oxide(ZnO) combination nanoparticles are reported to inhibit methicillin-resistant Staphylococcus aureus(MRSA) for the first time. SNs loaded with ZnO nanoparticles,which can produce free radicals, can cause severe damage to bacteria. ZnO nanoparticles not only provide free radicals in the combined nanostructures, which can inhibit the growth of bacteria, but also form nanorough surfaces with an irregular distribution of spikes on the SNs, which can enhance their adhesion to bacteria. Nanorough silica shell surfaces maintain the high activity and stability of small-sized ZnO nanoparticles and gather ZnO nanoparticles together to enhance production, which improves the efficiency of free radicals against the cytomembranes of bacterial cells. The enhanced adhesion of ZnO@SN nanoparticles to MRSA cells shortens the effective touching distance between free radicals and MRSA, which also improves antibacterial activity. As we expected, the ZnO@SN nanoparticles exhibit a better antibacterial effect than free ZnO nanoparticles against MRSA in vitro and in vivo. We also demonstrate that SNs loaded with ZnO nanoparticles can accelerate wound healing in MRSA skin inflammation models. This method of multilevel functionalization will be potentially applicable to the antibacterial field.

Hybrid photoanode films based on sparse ZnO rod array-TiO_2 nanoparticles in dye-sensitized solar cells

ZnO-TiO2 hybrid photoanodes were fabricated via the doctor-blade method by integrating vertically-grown sparse ZnO arrays with hydrothermal TiO2 nanoparticles. A special surface-coating technique was developed to deposit a thin TiO2 layer on the surface of ZnO rods. Microstructure, optical and photoelectrochemical performance of the hybrid photoanodes were investigated. The denser ZnO array exhibited bad filling behavior of nanoparticles in the interspace of ZnO rods, strong scattering and low conversion efficiency (0.27%). The sparser array showed a much better integrated microstructure, improved transmittance and high conversion efficiency (2.68%). The surface modification of ZnO rods by the TiO2 thin layer was found useful in improving the interfacial microstructure between the ZnO rod and the TiO2 bulk film, and the total conversion efficiency of 3.01% was achieved, higher than that of the pure TiO2 nanoparticle cell (2.93%). The increased scattering effects on the incident light, the enhanced electron transportation at TiO2/dye/electrolyte interface, and the inhabited recombination were responsible for this improvement.

Study of lanthanide doped zinc oxide nanoparticles synthesized via a sonochemical method

In this work, lanthanide doped zinc oxide nanoparticles synthesized in room-temperature ionic liquid via a sonochemical method have been studied. Firstly, the cavitation bubble temperatures in 1-butyl-3-methylimidazolium hexafluorophosphate (ImPF6) have been estimated by the methyl radical recombination method. The temperatures measured in ImPF6 are in the range of 3000-4000 K. Secondly, a facile method has been proposed to prepare lanthanide (Ⅲ) doped zinc oxide nanoparticles in ImPF6 via an ultrasonic irradiation. The nanomaterials are studied by transmission electron microscopy, X-ray diffraction, photoacoustic and luminescence techniques. The results show that the relaxation processes of the samples depend strongly on the lanthanide doping. Moreover, a mechanism is proposed to interpret the formation of lanthanide (Ⅲ) doped zinc oxide nanoparticles in the ImPF6 upon ultrasonic irradiation.

Tunability of Photonic Band Gaps in One- and Two-dimensional Photonic Crystals Based on ZnS Particles Embedded in TiO2 Matrix

Using the Maxwell-GarneR theory, the evolution of the refractive index of titanium dioxide （TiO2） doped with zinc sulfide （ZnS） particles is presented. The presence of the nano-objects in the host matrix allows us to obtain a new composite material with tunable optical properties. We find that the filling factor of ZnS nanoparticles greatly alters photonic band gaps （PBGs）. We have calculated also the photonic band structure for electromagnetic waves propagating in a structure consisting of ZnS rods covered with the air shell layer in 2D hexagonal and square lattices by the finite difference time domain （FDTD） method. The rods are embedded in the TiO2 background medium with a high dielectric constant. Such photonic lattices present complete photonic band gaps （CPBGs）. Our results show that the existence of the air shell layer leads to larger complete photonic gaps. We believe that the present results are significant to increase the possibilities for experimentalists to realize a sizeable and larger CPBG.