Nitrites are widely used in the food industry, particularly for the preservation of meat products. Controlling the nitrate content in food is an important task to ensure people’s health is not at risk; therefore, the search for, and research of, new materials that will modify the electrodes in the electrochemical sensors that detect and control the nitrate content in food products is an urgent task. In this paper, we describe the electrochemical behavior of a glass carbon electrode (GCE), modified with a Fe(II) tetra-tert-butyl phthalocyanine film (FePc(tBu)₄/GCE), and decorated with gold nanoparticles (Au/FePc(tBu)₄/GCE); this electrode was deposited using gas-phase methods. The composition and morphology of such electrodes were examined using spectroscopy and electron microscopy methods, whereas the main electrochemical characteristics were determined using cyclic voltammetry (CV) and amperometry (CA) methods in the linear ranges of CV 0.25–2.5 mM, CA 2–120 μM in 0.1 M phosphate buffer (pH = 6.8). The results showed that the modification of bare GCEs, with a Au/FePc(tBu)₄ heterostructure, provided a high surface-to-volume ratio, thus ensuring its high sensitivity to nitrite ions of 0.46 μAμM⁻¹. The sensor based on the Au/FePc(tBu)₄/GCE has a low limit of nitrite detection at 0.35 μM, good repeatability, and stability. The interference study showed that the proposed Au/FePc(tBu)₄/GCE exhibited a selective response in the presence of interfering anions, and the analytical capability of the sensor was demonstrated by determining nitrite ions in real samples of meat products.

Interest in iridium and platinum has been steadily encouraged due to such unique properties as exceptional chemical inertia and corrosion resistance, high biological compatibility, and mechanical strength, which are the basis for their application in medical practice. Metal-organic chemical vapor deposition (MOCVD) is a promising method to fabricate Ir and Pt nanomaterials, multilayers, and heterostructures. Its advantages include precise control of the material composition and microstructure in deposition processes at relatively low temperatures onto non-planar substrates. The development of MOCVD processes is inextricably linked with the development of the chemistry of volatile precursors, viz., specially designed coordination and organometallic compounds. This review describes the synthesis methods of various iridium and platinum precursors, their thermal properties, and examples of the use of MOCVD, including formation of films for medical application and bimetallics. Although metal acetylacetonates are currently the most widely used precursors, the recently developed heteroligand Ir(I) and Pt(IV) complexes appear to be more promising in both synthetic and thermochemical aspects. Their main advantage is their ability to control thermal properties by modifying several types of ligands, making them tunable to deposit films onto different types of materials and to select a combination of compatible compounds for obtaining the bimetallic materials.

Using gas-phase deposition (Physical Vapor Deposition (PVD) and Metal Organic Chemical Vapor Deposition (MOCVD)) methods, modern implant samples (Ti alloy and CFR-PEEK polymer, 30% carbon fiber) were functionalized with film heterostructures consisting of an iridium or gold sublayer, on the surface of which an antibacterial component (silver) was deposited: Ag/Ir(Au)/Ti(CFR-PEEK). The biocidal effect of the heterostructures was investigated, the effect of the surface relief of the carrier and the metal sublayer on antibacterial activity was established, and the dynamics of silver dissolution was evaluated. It has been shown that the activity of Ag/Ir heterostructures was due to high Ag⁺ release rates, which led to rapid (2–4 h) inhibition of P. aeruginosa growth. In the case of Ag/Au type heterostructures, the inhibition of the growth of P. aeruginosa and S. aureus occurred more slowly (from 6 h), and the antibacterial activity appeared to be due to the contribution of two agents (Ag⁺ and Au⁺ ions). It was found, according to the in vitro cytotoxicity study, that heterostructures did not exhibit toxic effects (cell viability > 95–98%). An in vivo biocompatibility assessment based on the results of a morphohistological study showed that after implantation for a period of 30 days, the samples were characterized by the presence of a thin fibrous capsule without volume thickening and signs of inflammation.

Ni(II) β-diketonate derivatives – β-iminoketonates with general formula Ni(RC(O)CHC(NH)R1)2 (R=R1=CH3, C(CH3)3; R=CF3, R1=CH3, C(CH3)3; R=C(OCH3)(CH3)2, R1=CH(CH3)2, C(CH3)3) and Ni(1,3-diaminopropane)(R2C(O)CHC(O)R3)2 (R2=C(CH3)3, R3=CF3, C(CH3)3) – were synthesized with high yields. The products are stable to air and moisture, and soluble in most common organic solvents. Elemental analysis, X-ray studies, and IR spectroscopy were used to characterize the synthesized compounds. The thermal properties of the compounds in the solid state were investigated by means of TG. The temperature dependence of the saturated vapor pressures was studied using the flow method. Thermodynamic parameters of the vaporization process, ΔHТ* and ΔS°Т*, were calculated. MOCVD test experiments were carried out at low pressure (10Torr) on Ta/Si substrates using Ni(i-tmhd)2 and Ni(pda)(tmhd)2 (i-Htmhd — 2,2,6,6-tetramethyl-4-imino-heptane-2-on, pda — 1,3-diaminopropan, Htmhd — 2,2,6,6-tetramethyl-heptane-3,5-dion) as precursors. The vaporization temperatures were 120°C for Ni(pda)(tmhd)2 and 155°C for Ni(i-tmhd)2. The substrate temperatures were 210–350°C. The Ni-containing films were investigated by means of X-ray diffraction analysis, SEM, and XPS