Nanoparticles have unique, size-dependent properties, which means they are widely used in various branches of industry. The ability to control the properties of nanoparticles makes these nanomaterials very interesting for medicine and pharmacology. The application of nanoparticles in medicine is associated with the design of specific nanostructures, which can be used as novel diagnostic and therapeutic modalities. There are a lot of applications of nanoparticles, e.g., as drug delivery systems, radiosensitizers in radiation or proton therapy, in bioimaging, or as bactericides/fungicides. This paper aims to introduce the characteristics of noble metal-based nanoparticles with particular emphasis on their applications in medicine and related sciences.

Trimethylphosphine (TMP) is demonstrated as a suitable 31 P MAS NMR probe molecule for determining accessibility, environment, and spatial distribution of oxidation-active oxidic metal species on solid catalysts quantitatively. It oxidizes to trimethylphosphine oxide (TMPO) at oxygen donor sites, which is demonstrated for oxides of copper, manganese, cobalt, and molybdenum. At loadings <2 wt % of Mo a direct quantitative correlation between TMPO quantity and accessible metal oxide content is observed. Exceeding 2 wt % results in a gradual agglomeration and thus decreases the amount of available oxidative sites, probed as a decay of the amount of TMPO formed. Additionally, the spatial distribution of oxides neighboring species could be inferred. The solid TMPO deposited near MoO x species was very sensitive to extra framework aluminum (EFAL) as well as Brønsted acid sites in close proximity, depending on Mo loading. Thus, the TMP method provides unprecedented insights into the surface chemistry of oxidative metal oxide catalysts.

No abstract

In this study, the effect of urbanization and environmental pollution on qualitative (structural) and quantitative changes of the Corylus avellana (hazel) pollen was investigated using scanning electron microscopy, Fourier Transform Infrared (FTIR) spectroscopy and curve-fitting analysis of amide I profile. The obtained spectroscopic results show significant variations in the fraction of proteins in the hazel pollen, which probably depend on various degrees of anthropopression. Our results suggest that alterations in the chemical composition of pollen, induced by urbanization and air pollutants, may intensify the allergenic potential and may cause the increase in the incidence of allergies in people. Mutations in nucleic acids are accompanied by a number of molecular changes leading to the formation of allergenic proteins. It seems that the type of habitat, where the pollen grew, affects the individual differentiation. Indeed, it was found that in the site exhibiting low pollution, the hazel pollen contain a lower amount of proteins than to the ones from a site with high anthropopression. Hence, FTIR spectroscopy and curve-fitting analysis of amide I profile can be successfully applied as tools for identifying quantitative and qualitative changes of proteins in hazel pollen.Graphical Abstract Anthropogenic factors such as air pollution and urbanization lead to changes in structure and chemical composition of hazel pollen. Fourier Transform Infrared spectroscopy (FTIR) and Gaussian analysis showed structural changes in hazel pollen collected from sites with different absorbance values of individual chemical functional groups and changes in the secondary structure of proteins of the pollen.

Nickel–silver core–shell (Ni@Ag) nanoparticles (NPs) were formed in a two-step process: (1) the formation of a dispersion of Ni NPs; and (2) the transmetalation (galvanic displacement) reaction, where the surface of the Ni NPs acted as the reducing agent of Ag ions. Ni NPs were synthesized by the ‘wet’ chemical method, i.e., by the reduction of metal ions by using NaBH4 as the reducing agent. The influence of the concentration of polymeric stabilizer, reducing agent and Ag precursor on the properties of synthesized NPs was evaluated. In the optimal condition of synthesis, Ni@Ag NPs with about 50 and 210 nm-diameter Ni core coated with a thin (∼10–20 nm) Ag shell, were obtained. Finally, the stability of the synthesized spherical-shaped Ni@Ag NPs was tested and the results indicate long-term stability against aggregation and Ni oxidation. Thus, the resulting NPs are promising candidates for application in electronic devices, e.g., as components of conductive inks or pastes.

Aim: To investigate the fungicidal activity of rod-shaped gold nanoparticles (AuR NPs) against Candida strains isolated from hematooncological patients and representative strains of filamentous fungi. Methods: Colony-counting assays, colorimetric and fluorometric methods and atomic force microscopy were employed. Results: AuR NPs were characterized by their potent fungicidal activity against all tested isolates, regardless of the species or drug susceptibility, at concentrations that are nontoxic to the host cells. The membrane-permeabilizing properties of AuR NPs and induction of reactive oxygen species were recognized as crucial for fungicidal activity. Conclusions: The results provide a rationale for the development of nonspherical Au NPs as effective antifungals or drug-delivery carriers to improve therapy for fungal infections.

Bulk semiconductors doped with copper ions have been heavily studied and employed as phosphors in early display technologies. The properties of copper-doped semiconductor nanostructures are much less studied. In particular, the spin properties of photoexcited carriers in copper-doped colloidal quantum dots are virtually unknown. Understanding the spin processes in these materials can lead to applications in novel information technologies. Moreover, the spin structure of the excited states in Cu-doped dots is analogous to that of Cu(I) molecular complexes, which are widely studied with respect to applications in organic light-emitting diodes. Thus, understanding the spin properties of Cu-doped dots can have broad ramifications for other material systems. In this work, we study the dynamics of spin relaxation processes in photoexcited Cu-doped CdSe colloidal quantum dots at helium temperatures and in magnetic fields up to 8 T. We find that a spin polarization is induced by application of the magnetic field. However, this polarization develops extremely slowly: about 2 orders of magnitude slower than in reference Cu-free CdSe dots, at time scales on the order of 1 μs at 2 K and fields below 1 T. As the magnetic field and/or temperature is increased the spin relaxation accelerates, but in the entire field and temperature range remains much slower than in CdSe dots. We discuss various mechanisms responsible for the development of the spin polarization and conclude that the slow spin dynamics is related to the nature of the photoexcited state, which limits the carrier interaction with uncompensated spins at the dot surface. Our results thus underline the role of surface states in spin relaxation processes in colloidal quantum dots in general.

Copper indium sulfide colloidal quantum dots are in focus of the nanocrystal community as their optical properties make them exciting candidates for applications in bioimaging and biosensing, solar cells, luminescent solar concentrators, and lighting. However, fulfilling this application potential is hampered by poor understanding of the mechanism of light emission by these dots. In this work, we study temperature and magnetic field dependent photoluminescence (PL) dynamics and spin dynamics at cryogenic temperatures. We cast our experimental observations against two prevailing models of PL in CuInS2 quantum dots: an excitonic mechanism and a free-to-bound mechanism, in which a delocalized electron recombines with a hole localized at a copper ion. We unambiguously show that the PL occurs as the result of the free-to-bound mechanism.