Preparation and characterization of Ni-doped ZnO particles via a bioassisted process

Ecotoxicity of doped zinc oxide nanoparticles: Perspectives on environmental safety

Studies on the ecotoxicity of doped zinc oxide nanoparticles (ZnO NPs) are recent, with the first publications starting in 2010. In this sense, this is the first study that comprehensively reviews the ecotoxicological effects of ZnO NPs doped with lanthanide elements to fill this literature gap. This research explores a multifaceted question at the intersection of nanotechnology, toxicology, and environmental science. Different types of dopants commonly used for ZnO doping were investigated in this review, focusing on the ecotoxicological effects of lanthanides as dopants. Bacteria were the main class of organisms used in ecotoxicological studies, since antimicrobial activity of these nanomaterials is extensively explored to combat the imminent problem of resistant bacteria, in addition to enabling the safe use of these nanomaterials for biomedical applications. Doping appears to exhibit greater efficacy when compared to undoped ZnO NPs in terms of antimicrobial effects; however, it cannot be said that it has no impact on non-target organisms. An extensive examination of the literature also establishes the importance and need to evaluate the effects of doped ZnO NPs on organisms from different environmental compartments in order to identify their potential impacts. We underscore the dearth of research information regarding the environmental toxicity/ecotoxicity of doped ZnO nanoparticles across various ecological levels, thereby limiting the extrapolation of findings to humans or other complex models. Therefore, we emphasize the urgency of a multi-parameter assessment for the development of sanitary and environmentally safe nanotechnologies.

Influence of Sn4+ ion on band gap tailoring, optical, structural and dielectric behaviors of ZnO nanoparticles

II-VI semiconductors are being attracted due to excellent optical and electronic behaviors when they utilize for device fabrication. Among II-VI semiconductors, Zinc oxide finds cutting-edge results for various applications with a lack of toxicity. Sn⁴⁺ ion incorporated ZnO nanoparticles have been synthesized using a soft chemical route and characterized for the investigation of properties like structural, morphological, elemental, optical and dielectric responses. The prepared ZnO had a hexagonal structure and the particles size reduces by the influence of Sn⁴⁺ ion: this reduction rate increases for the increase of doping ratio. The average particles size was estimated within 24-34 nm. TEM, HRTEM and SEM results corroborate the structural aspects noticed using XRPD study. UV-vis study results showed that a blue shift on the optical band gap was received for high doping concentration (10 at.%) of Sn⁴⁺. PL peaks were observed in the UV region for 0 at.% and 2 at.% Sn⁴⁺ doped ZnO nanoparticles, and the peak position was shifted from UV to violet and blue region for 10 at.% Sn⁴⁺ doped ZnO nanoparticles. The dielectric permittivity was reduced due to the addition of Sn⁴⁺ ions. The AC conductivity was increased for higher doping concentrations. The Sn⁴⁺ ion incorporated ZnO nanoparticles shall be useful for various applications including LED fabrication for blue emission and also it is suitable to act as a buffer material in solar panel.

Facile preparation and bifunctional imaging of Eu-doped GdPO4 nanorods with MRI and cellular luminescence

Eu-doped GdPO₄ NRs coated by silk fibroin have been prepared in a template of silk fibroin (SF) peptides via a mineralization process. A growth mechanism of SF-NRs is proposed to explain their stronger luminescence, better cyto-compatibility and higher longitudinal relaxivity r₁.

Synthesis and neuro-cytocompatibility of magnetic Zn-ferrite nanorods via peptide-assisted process

In order to obtain magnetic nanorods (MNRs) with the neuro-cytocompatibility, silk-fibroin (SF)-coated Zn-ferrite NRs are successfully prepared via a mineralization process, and their saturation magnetization is 32emu g(-)(1). After the mineralization of 2d and 4d in the mixed solution of the concentrations of 15w/w% SF and 0.01M HCl, the lengths of NRs are ∼220nm and ∼2μm, respectively. Cell tests of NRs with 220nm length showed that the as-prepared Zn-ferrite NRs hardly produced toxicity on Escherichiacoli, Staphylococcusaureus, L929, and PC12 cells. The results of the outgrown neurites from PC12 cells indicated that the neurite length and the number of neurites were not significantly decreased at the low concentrations of SF-coated NRs (less than 0.25mg mL(-)(1)) in 1-5d culture time. TEM images of cell ultrathin sections indicated that, although Zn-ferrite NRs were split in the cytosol for 5d at the NR concentrations of 0.125mg mL(-)(1), some integrated mitochondria in a neurite suggested that SF-coated NRs inside cells did not influence the extension activity of neurites. Based on the good neuro-cytocompatibility and magnetic property of Zn-ferrite NRs, their potential applications in safe cell manipulation and axon guidance can be envisioned.