Synthesis and Characterization of Zinc Oxide and Zinc Oxide Doped with Chlorine Nanoparticles as Novel <i>α</i>-Amylase Inhibitors

In this study we used a chemical solution method from oxalic acid (OX. acid) and zinc acetate (ZnAc) to prepare Zinc Oxide nanoparticles (ZnONPs) and Zinc Oxide nanoparticles doped with Chlorine (Cl:ZnONPs). The characterizations (FTIR, X-ray, SEM, TEM) of ZnONPs and Cl:ZnONPs were determined. Amylase inhibitors of ZnONPs and Cl:ZnONPs also were determined. SEM indicated that the ZnONPs and Cl:ZnONPs have an average particle size of 46.65 - 74.64 nm. TEM images of the ZnONPs and Cl:ZnONPs showed the round shaped. Compounds b, d and e exhibited significant inhibitory activity against amylase enzyme (from 69.21 ± 1.44 to 76.32 ± 0.78), respectively, and were comparable with that of acarbose (86.32 ± 0.63) at 1000 μg, thereby, projecting ZnONPs and Cl:ZnONPs as α-amylase inhibitors.

Coumarin derivative dye sensitized NaYGdF4:Yb,Er nanoparticles with enhanced NIR Ⅱ luminescence for bio-vascular imaging

Lanthanide-doped biocompatible nanoparticles have promising applications in near-infrared second region imaging due to their high chemical stability,enhanced photostability and sharp emission bandwidth.However,the weak light absorption capacity limits the application of rare-earth nanoparticles(RENPs) for bioimaging.We prepared a coumarin-derived dye sensitized NaYGdF4:Yb,Er nanoparticle probe,in which the organic dye enhances photon absorption through the sensitization process,improving the luminescence efficiency of the rare earth particles near 1000 and 1500 nm.In addition,good water solubility and stability of the probe are imparted by coating the particles with amphiphilic polymers distearoyl phosphatidylethanolamine-polyethylene glycol(DSPE-PEG) and polyacrylic acid.This composite probe with good biocompatibility and NIR Ⅱ luminescence properties can be used for vascular imaging,providing a tool for the detection of hematologic-related diseases.

D-type neuropeptide decorated AIEgen/RENP hybrid nanoprobes with light-driven ROS generation ability for NIR-Ⅱ fluorescence imaging-guided through-skull photodynamic therapy of gliomas

Glioma is one of the most common malignant tumors of the central nervous system,leading high mortality rates in human.Aggregation-induced emission(AIE)photosensitizers-based photodynamic therapy(PDT)has emerged as a promising therapeutic strategy for least-invasive treatment of glioma,which involves local irradiation of the tumor using an external near-infrared(NIR)laser.Unfortunately,most AIE photosensitizers suffered from poorly penetration of the visible light excitation,bad spatiotemporal resolution in deep tissues and low efficient blood-brain barrier(BBB)crossing ability,which greatly limited the clinical practice of AIE photosensitizers for especially deep-seated brain tumor treatment.In this work,we developed a multifunctional NIR-driven theranostic agent through hybrid of AIE photosensitizers TIND with rare-earth doping nanoparticles(RENPs)NaGdF4:Nd/Yb/Tm with up/down dual-mode conversion luminescence.The theranostic agent was further decorated with D-type neuropeptide DNPY for crossing BBB and targeting glioma.Under the 808-nm light irradiation,the down-conversion NIR-II luminescence could indicate the position glioma and the upconversion NIR-I luminescence could trigger the AIE photosensitizers producing reactive oxygen species to inhibit orthotopic glioma tumor growth in situ.These results demonstrate that the integration of Dtype neuropeptide,AIE photosensitizers and RENPs could be promising candidates for in vivo NIR-II fluorescence image-guided through-skull PDT treatments of brain tumors.

Effect of solvent on luminescence properties of re-dispersible LaF_3:Ln^(3+)(Ln^(3+)=Eu^(3+),Dy^(3+),Sm^(3+) and Tb^(3+)) nanoparticles

LaF3：Ln3＋ （Eu3＋, Dy3＋, Sm3＋ and Zb3＋） nanoparticles were prepared in different solvents such as water, EG （ethylene gly- col）, DMSO （dimethyl sulfoxide） and their mixed solvents at a relatively low temperature of 150 ~C by simple chemical route. All the prepared samples showed hexagonal phase and exhibited spherical morphology. The highest ltmainescence intensity was observed for the samples prepared in EG than the samples prepared in other solvents. However, the sample prepared in water showed anomalously higher luminescence intensity than that of the sample prepared in DMSO.

Facile Synthesis as well as Structural, Raman, Dielectric and Antibacterial Characteristics of Cu Doped ZnO Nanoparticles

Here, undoped and Cu doped ZnO nanoparticles(NPs) have been prepared by chemical co-precipitation technique. X-ray diffraction(XRD) results reveal that Cu ions are successfully doped into ZnO matrix without altering its wurtzite phase. The single wurtzite phase of ZnO is retained even for 10 wt% Cu doped ZnO sample. It is observed from the electron microscopy results that higher level of Cu doping varies the morphology of ZnO NPs from spherical to flat NPs. Moreover, the particle size is found to increase with the increase in Cu doping level. Raman spectroscopy results further confirm that Cu dopant has not altered the wurtzite structure of ZnO. Impedance spectroscopy results reveal that the dielectric constant and dielectric loss have increasing trend with Cu doping. Cu doping has been found to slightly decrease the bactericidal potency of ZnO nanoparticles.

Rare Earth Doped Optical Fibre From Oxide Nanoparticles

Rare earth (RE) doped optical fibres were fabricated by using RE oxides coated silica nanoparticles. The fibre properties are comparable to those prepared by conventional techniques. The process offers better control over RE incorporation and homogeneity in the preform.

Characterization of B site codoped LaFeO_3 nanoparticles prepared via co-precipitation route

LaFe（1-x-y）CoxPdyO3 [（x, y） =（0, 0）,（0.40, 0）,（0.38, 0.05）] nanoparticles were synthesized via a co-precipitation route using ammonium hydroxide, sodium hydroxide and ammonium carbonate as the precipitant and calcination at different temperatures to study the compositional driven structural changes in lanthanum ferrites.Analysis of X-ray diffraction（XRD） patterns confirms the formation of single-phase perovskite structure and existence of orthorhombic Pnma symmetry for calcined powders. Field emission scanning electron microscope（FESEM） observations show that Pd-doped powders yield finer particles along with narrower particle size distribution compared with LaFeO3 and LaFe（0.6）Co（0.4）O3. Moreover,using ammonia as the precipitant leads to a smaller mean particle size of powders compared to NaOH, as well as significant difference in morphology of the particles.Raman analysis reveals that both Co and Pd atoms substitute Fe site in perovskite structure with shifting of phonon modes. Comparing Raman spectra demonstrates the presence of more oxygen vacancies in Pd-doped perovskites. It can be concluded from the results that Pd is successfully incorporated into the perovskite structure by co-precipitation method.

Answer to comments on “Fabrication and photovoltaic conversion enhancement of graphene/n-Si Schottky barrier solar cells by electrophoretic deposition”

Here,we reply to comments by Valentic et al.on our paper published in Electrochimica Acta（2014,130：279）.They commented that Au nanoparticles played the dominant role on the whole cell＇s performances in our improved graphene/Si solar cell.We argued that our devices are Au-doped graphene/n-Si Schottky barrier devices,not Au nanoparticles（film）/n-Si Schottky barrier devices.During the doping process,most of the Au nanopatricles covered the surfaces of the graphene.Schottky barriers between doped graphene and n-Si dominate the total cells properties.Through doping,by adjusting and tailoring the Fermi level of the graphene,the Fermi level of n-Si can be shifted down in the graphene/Si Schottky barrier cell.They also argued that the instability of our devices were related to variation in series resistance reduced at the beginning due to slightly lowered Fermi level and increased at the end by the serf-compensation by deep in-diffusion of Au nanoparticles.But for our fabricated devices,we know that an oxide layer covered the Si surface,which makes it difficult for the Au ions to diffuse into the Si layer,due to the continuous growth of SiO2 layer on the Si surface which resulted in series resistance decreasing at first and increasing in the end.