Study of influence of metal ions on CdTe/H2O2 chemiluminescence

Water-soluble CdTe nanocrystals (NCs) were synthesized and applied to study the effect of metal ions on chemiluminescence (CL) of the CdTe/H₂O₂ system. The effects of experimental factors, such as pH, particle sizes of CdTe and reagent concentration, on kinetics curve and CL intensity of the CdTe/H₂O₂ system were examined. The results showed that under the optimal conditions Ba²⁺, Ca²⁺, Fe²⁺, Pb²⁺ and Cu²⁺ enhanced the CL intensity, and Cr³⁺, Ni²⁺, Zn²⁺ and Ag⁺ inhibited the CL intensity.     

Tunable variation of optical properties of polymer capped gold nanoparticles

Optical properties of polymer capped gold nanoparticles of various sizes (diameter 3–6 nm) have been studied. We present a new scheme to extract size dependent variation of total dielectric function of gold nanoparticles from measured UV-Vis absorption data. The new scheme can also be used, in principle, for other related systems as well. We show how quantum effect, surface atomic co-ordination and polymer-nanoparticle interface morphology leads to a systematic variation in interband part of the dielectric function of gold nanoparticles, obtained from the analysis using our new scheme. Careful analysis enables identification of the possible changes to the electronic band structure in such nanoparticles.     

Catalytic PtPd bimetal nanocrystals with high-index facets for radiation injury repair

Radiotherapy is one of the most important clinical cancer treatments,which works mainly by delive ring a prescribed radiation dose to the tumor tissues.However,high doses of radiation may also lead many irreversible damages to the surrounding normal tissues.Thereby,how to effectively reduce these sideeffects has been a significant factor in influencing cancer therapeutic effect.In this work,we synthesized the hollow PtPd nanocubes with high-index facets,and investigated the radiation protection capability in vitro and in vivo.Our results showed the PtPd nanocrystals can decrease the ROS level and improve the survival rate of radiated cells.Meanwhile,survival rate of radiated mice can significantly increase from 0 to 30%after PtPd treatment.Consequently,the enzyme and ROS level in radiated mice can be recovered.     

Temperature dependence of photoluminescence and magnetic properties in Yb-doped ZnS nanocrystals

Zinc sul?de semiconductor nanocrystals doped with Yb³⁺ ions have been prepared through a chemical precipitation method using PVP (polyvinylpyrrolidone) as a capping agent. The structure of the nanoparticles has been analyzed by X-ray diffraction (XRD). The average size of the nanoparticles is found to be 3.7±0.4 nm. Photoluminescence spectra were recorded for doped ZnS nanoparticles as a function of temperature between 9 and 300 K. The results suggest that two emission bands have been observed at different temperatures. The width of 1.269 eV peak increases as temperature is raised. A shift of lower energy emission band has been observed with the change of temperature. Moreover, the magnetic measurement showed that the sample exhibits paramagnetic behavior.     

Evidence for an internal field in CdSe/CdS nanorods by time resolved and single rod experiments

In this contribution we report on an optical nonlinearity featuring colloidal seeded grown CdSe/CdS nanorods (NRs). It consists of a photoluminescence (PL) blueshift of single rod spectra with increasing laser power and a transient, power-dependent redshift of the spectra studied by time resolved PL measurement, strictly related to the multicarrier scattering occurring at high excitation density. We attribute this nonlinearity to a photo-induced screening of an internal field, originating from the piezoelectric polarization induced at the core/shell interface.     

Size-dependent denaturing kinetics of bovine serum albumin adsorbed onto gold nanospheres

We have used localized surface plasmon resonance (LSPR) to monitor the kinetics of thermal denaturing of bovine serum albumin (BSA) adsorbed onto gold nanospheres of size 5 nm-100 nm. The effect of the protein on the LSPR was monitored by visible extinction spectroscopy. The wavelength of the peak extinction (resonance) is affected by the conformation of the adsorbed protein layer, and as such can be used as a very sensitive probe of thermal denaturing that is specific to the adsorbed (as opposed to free) protein. The time dependence of the denaturing is measured in the temperature range 60 °C–70 °C, and the lifetimes are used to calculate an activation barrier for thermal denaturing. The results show that thermally activated denaturing of proteins adsorbed onto nanoparticles has a nanoparticle-size-dependent activation barrier, and this barrier increases for decreasing particle size. This may have important implications for other protein-nanoparticle interactions.     

A distinct hollow spindle-like CdIn2S4 photocatalyst for high-efficiency tetracycline removal

Due to the massive release of antibiotics into the environment, it is of great emergency to find an effective approach to deal with antibiotic-containing wastewater. Photocatalytic technology, benefiting from its low cost and high efficiency, is deemed to be an appealing strategy. Photocatalytic-induced production of reactive oxygen species (ROS) is a promising but challenging prospect in water purification and environmental remediation. Herein, we fabricated a spindle-like hollow CdIn₂S₄ (HCIS) photocatalytic system for high-efficiency tetracycline removal. Targeting MIL-88A (Fe) as a template, the obtained CdIn₂S₄ photocatalysts reserved intrinsic spindle-like morphology. Compared with Bulk CdIn₂S₄ (BCIS), this unique hollow structure enhanced light absorption capacity and boosted carriers separation. As a result, the photodegradation efficiency reached over 94.5% within 40 min under visible light illumination. The degradation rate constant was four times higher than that of pristine CdIn₂S₄. We believe this work will endow some lights for the design of hollow catalysts in other environmental applications.     

单源前体合成水溶性的CdS和ZnS纳米晶

0引言量子点(QuantumDots)一般指半径小于或接近玻尔激子半径的半导体纳米晶颗粒。和有机染料分子相比,无机半导体纳米晶的带隙宽度可通过简单     

CdS:Mn/SiO2复合纳米颗粒的反常的磁学特性

采用反胶束法,合成了硅土包裹的Mn2+掺杂的CdS纳米颗粒。利用高分辨透射电镜(HRTEM)和电子自旋共振谱 (EPR) 对这些纳米颗粒的结构进行了表征。利用超导量子干涉磁力计（SQUID）测量了这些纳米颗粒在低温下的磁学特性。研究结果表明：扩散在硅土基质中的CdS:Mn纳米颗粒的磁滞回线相对于磁场轴有明显的偏移,而有致密包裹层SiO2的CdS:Mn纳米颗粒却使磁滞回线的偏移消失,对于磁性纳米颗粒在磁化过程中出现的这一奇特的现象进行了合理的解释。