Heterostructures Based on Cobalt Phthalocyanine Films Decorated with Gold Nanoparticles for the Detection of Low Concentrations of Ammonia and Nitric Oxide

This work is aimed at the development of new heterostructures based on cobalt phthalocyanines (CoPc) and gold nanoparticles (AuNPs), and the evaluation of the prospects of their use to determine low concentrations of ammonia and nitric oxide. For this purpose, CoPc films were decorated with AuNPs by gas-phase methods (MOCVD and PVD) and drop-casting (DC), and their chemiresistive sensor response to low concentrations of NO (10–50 ppb) and NH3 (1–10 ppm) was investigated. A comparative analysis of the characteristics of heterostructures depending on the preparation methods was carried out. The composition, structure, and morphology of the resulting hybrid films were studied by X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma atomic emission (ICP-AES) spectroscopy, as well as electron microscopy methods to discuss the effect of these parameters on the sensor response of hybrid films to ammonia and nitric oxide. It was shown that regardless of the fabrication method, the response of Au/CoPc heterostructures to NH3 and NO gases increased with an increase in the concentration of gold. The sensor response of Au/CoPc heterostructures to NH3 increased 2–3.3 times compared to CoPc film, whereas in the case of NO it increased up to 16 times. The detection limits of the Au/CoPc heterostructure with a gold content of ca. 2.1 µg/cm2 for NH3 and NO were 0.1 ppm and 4 ppb, respectively. It was shown that Au/CoPc heterostructures can be used for the detection of NH3 in a gas mixture simulating exhaled air (N2—74%, O2—16%, H2O—6%, CO2—4%)

Heterostructures Based on Cobalt Phthalocyanine Films Decorated with Gold Nanoparticles for the Detection of Low Concentrations of Ammonia and Nitric Oxide

This work is aimed at the development of new heterostructures based on cobalt phthalocyanines (CoPc) and gold nanoparticles (AuNPs), and the evaluation of the prospects of their use to determine low concentrations of ammonia and nitric oxide. For this purpose, CoPc films were decorated with AuNPs by gas-phase methods (MOCVD and PVD) and drop-casting (DC), and their chemiresistive sensor response to low concentrations of NO (10–50 ppb) and NH3 (1–10 ppm) was investigated. A comparative analysis of the characteristics of heterostructures depending on the preparation methods was carried out. The composition, structure, and morphology of the resulting hybrid films were studied by X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma atomic emission (ICP-AES) spectroscopy, as well as electron microscopy methods to discuss the effect of these parameters on the sensor response of hybrid films to ammonia and nitric oxide. It was shown that regardless of the fabrication method, the response of Au/CoPc heterostructures to NH3 and NO gases increased with an increase in the concentration of gold. The sensor response of Au/CoPc heterostructures to NH3 increased 2–3.3 times compared to CoPc film, whereas in the case of NO it increased up to 16 times. The detection limits of the Au/CoPc heterostructure with a gold content of ca. 2.1 µg/cm2 for NH3 and NO were 0.1 ppm and 4 ppb, respectively. It was shown that Au/CoPc heterostructures can be used for the detection of NH3 in a gas mixture simulating exhaled air (N2—74%, O2—16%, H2O—6%, CO2—4%)

Biological Studies of New Implant Materials Based on Carbon and Polymer Carriers with Film Heterostructures Containing Noble Metals

This paper presents pioneering results on the evaluation of noble metal film hetero-structures to improve some functional characteristics of carbon-based implant materials: carbon-composite material (CCM) and carbon-fiber-reinforced polyetheretherketone (CFR-PEEK). Metal-organic chemical vapor deposition (MOCVD) was successfully applied to the deposition of Ir, Pt, and PtIr films on these carriers. A noble metal layer as thin as 1 µm provided clear X-ray imaging of 1–2.5 mm thick CFR-PEEK samples. The coated and pristine CCM and CFR-PEEK samples were further surface-modified with Au and Ag nanoparticles (NPs) through MOCVD and physical vapor deposition (PVD) processes, respectively. The composition and microstructural features, the NPs sizes, and surface concentrations were determined. In vitro biological studies included tests for cytotoxicity and antibacterial properties. A series of samples were selected for subcutaneous implantation in rats (up to 3 months) and histological studies. The bimetallic PtIr-based heterostructures showed no cytotoxicity in vitro, but were less biocompatible due to a dense two-layered fibrous capsule. AuNP heterostructures on CFR-PEEK promoted cell proliferation in vitro and exhibited a strong inhibition of bacterial growth (p < 0.05) and high in vitro biocompatibility, especially Au/Ir structures. AgNP heterostructures showed a more pronounced antibacterial effect, while their in vivo biocompatibility was better than that of the pristine CFR-PEEK, but worse than that of AuNP heterostructures