Human serum albumin (HSA) is one of the most frequently immobilized proteins on the surface of carriers, including magnetic nanoparticles. This is because the drug–HSA interaction study is one of the basic pharmacokinetic parameters determined for drugs. In spite of many works describing the immobilization of HSA and the binding of active substances, research describing the influence of the used support on the effectiveness of immobilization is missing. There are also no reports about the effect of the support drying method on the effectiveness of protein immobilization. This paper examines the effect of both the method of functionalizing the polymer coating covering magnetic nanoparticles (MNPs), and the drying methods for the immobilization of HSA. Albumin was immobilized on three types of aminated chitosan-coated nanoparticles with a different content of amino groups long distanced from the surface Fe3O4-CS-Et(NH2)1–3. The obtained results showed that both the synthesis method and the method of drying nanoparticles have a large impact on the effectiveness of immobilization. Due to the fact that the results obtained for Fe3O4-CS-Et(NH2)2 significantly differ from those obtained for the others, the influence of the geometry of the shell structure on the ability to bind HSA was also explained by molecular dynamics.

Graphene is a material gaining attention as a candidate for new application fields such as chemical sensing. In this review, we discuss recent advancements in the field of hydrogen gas sensors based on graphene. Accordingly, the main part of the paper focuses on hydrogen gas sensors and examines the influence of different manufacturing scenarios on the applicability of graphene and its derivatives as key components of sensing layers. An overview of pristine graphene customization methods is presented such as heteroatom doping, insertion of metal/metal oxide nanosized domains, as well as creation of graphene-polymer blends. Volumetric structuring of graphene sheets (single layered and stacked forms) is also considered as an important modifier of its effective use. Finally, a discussion of the possible advantages and weaknesses of graphene as sensing material for hydrogen detection is provided.

The manuscript presents results on the influence of external pressure on graphene exfoliation and subsequent 3D structuring by means of liquid-phase exfoliation. In contrast to known and applied exfoliation methods, the current study exploits the enhancement of splitting forces caused by the application of high pressure. The manufacturing pathway allowed to increase the surface area from 750 m2/g (nanoplatelets) to ca. 1100 m2/g (after 3D structuring). Electrochemical studies revealed that the 3D graphene materials were active in the oxygen reduction reaction (ORR). The outstanding ORR activity of 3D structured graphene materials should not be ascribed to heteroatom catalytic centers since such heteroatoms were successively removed upon increasing the carbonization temperature. XPS data showed that the presence of transition metals and nitrogen (usually regarded as catalytic centers) in G-materials was marginal. The results highlight the importance of structural factors of electrodes in the case of graphene-based materials for Zn–air batteries and ORR.

The following paper presents the synthesis of nitrogen-rich carbon foams (N-CFO) from amino acids through their thermal decomposition in the presence of solid and removable nanoparticles (template). N-CFO were synthesized by carbonizing L-lysine as the carbon phase precursor and using a hard template of CaCO 3 (added as nano-sized powder). The carbonization process was carried out in a temperature range of 700-900°C, under the flow of nitrogen. The results show that the textural and chemical properties among other nitrogen content of the N-CFO can be controlled by manipulating carbonization temperature. The obtained N-CFO were either micro-or mesoporous matrixes (open porosity) with high nitrogen content in the range from 4.1 to 12.4 wt%. The walls of the produced N-CFO had a thickness up to 10 nm. The metal-free catalysts such as N-rich carbon foams are valuable materials in oxygen reduction reaction, which is a key reaction for metal-air batteries. It was found that a four-electron reduction process is predominant.

Phototherapies, including photodynamic therapy (PDT), have been widely used in the treatment of various diseases, especially for cancer. However, there is still a lack of effective, safe photosensitizers that would be well tolerated by patients. The combination of several methods (like phototherapy and hyperthermia) constitutes a modern therapeutic approach, which demands new materials based on components that are non-toxic without irradiation. Therefore, this study presents the synthesis and properties of novel, advanced nanomaterials in which the advantage features of the magnetic nanoparticles and photoactive compounds were combined. The primary purpose of this work was the synthesis of magnetic nanoparticles coated with biocompatible and antitumor polysaccharide-levan, previously unknown from scientific literature, and the deposition of potent photosensitizerzinc(II) phthalocyanine on their surface. In order to better characterize the nature of the coating covering the magnetic core, the atomic force microscope analysis, a contact angle measurement, and the mechanical properties of pure levan and its blend with zinc(II) phthalocyanine films were investigated. This magnetic nanomaterial revealed the ability to generate singlet oxygen upon exposure to light. Finally, preliminary toxicity of obtained nanoparticles was tested using the Microtox® testwith and without irradiation.

No abstract

The paper presents results on the three-dimensional (3D) functionalization of graphite-originated flakes to graphene by carbonization of specific precursors in the presence of a hard template. In situ precipitated Na 2 CO 3 nanocrystals or CaCO 3 nano-powder were used as a hard template. Graphene flakes were obtained by a wet chemistry exfoliation of commercial graphite. The flakes were premixed with a non-specific binder and the hard template and then carbonized at temperatures of 700 to 800 °C under the flow of nitrogen. The addition of a template allowed to increase the surface area up 287 m 2 /g for the Na 2 CO 3 template and 333 m 2 /g in the case of CaCO 3 , while the surface area of 25 m 2 /g was noted for the raw graphite. Several instrumental methods were applied for the characterization of the obtained 3D-graphene materials: combustion elemental analysis, SEM, HRTEM, XPS, Raman spectroscopy and low-temperature adsorption of nitrogen. The effect of the addition of a template and the carbonization temperature on the surface area of the 3D structured graphene was demonstrated. The wet-chemistry method led to an efficient deglomeration of graphene flakes to double (DLG) and few (FLG) layered graphene. The proposed method is inexpensive.

Abstract