Introduction: This study investigated the incorporation of Amphipterygium adstringens ethanolic extract into the synthesis of copper oxide nanoparticles (CuO+Aa) and evaluates their antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and carbapenem-resistant Acinetobacter baumannii (CRAB). To assess the impact of the extract, chemically synthesized CuO nanoparticles (CuO-NPs) and the extract alone were also tested. Both CuO-NPs and A. adstringens are known for their antimicrobial properties. Methods: CuO+Aa nanoparticles were synthesized using A. adstringens extract and characterized through Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), Zeta Potential, Thermogravimetric Analysis (TGA), and X-ray Diffraction (XRD), and compared to CuO-NPs. The influence of the extract was analyzed using Inductively Coupled Plasma Mass Spectroscopy (ICP-MS), UV-Vis, FTIR, Raman, and Nuclear Magnetic Resonance Spectroscopy (NMR). Antibacterial effects were tested using the microdrop technique and biofilm inhibition. Bacterial structural changes were observed via Scanning Electron Microscopy (SEM), and cytotoxicity was measured through hemolysis assays. Results: CuO+Aa nanoparticles were smaller (3.46 nm) than CuO-NPs (5.32 nm). TGA indicated improved thermal degradation in CuO+Aa, suggesting incorporation of organic compounds. XRD revealed a shift from CuO to a mixed CuO-Cu₂O phase (75.15%– 24.84%) in CuO+Aa due to the functional groups present in the extract. Antibacterial assays showed that CuO+Aa inhibited MRSA and CRAB by 77% and 49%, respectively, using only 17.5 ppm of copper oxides—significantly lower than CuO-NPs, which required 150 ppm to achieve 96% and 78% inhibition. SEM revealed bacterial surface damage, including roughness, perforations, and cell wall collapse. All treatments showed low cytotoxicity (< 2% hemolysis). Biofilm formation increased by 180% in MRSA and 131% in CRAB. Conclusion: A. adstringens ethanolic extract enhances CuO nanoparticle synthesis, reducing size and maintaining strong antibacterial activity with low toxicity. CuO+Aa represents a promising candidate for future biomedical applications against resistant pathogens.

Absorbent materials are being developed to replace semiconductor materials such as p‐type silicon, GaAs, CdTe, and quaternary compounds such as CIGS (copper indium gallium selenide). Cu₂O is a potential candidate because it is non‐toxic, inexpensive, an abundant compound in the Earth’s crust, and has good optical properties, such as a high absorption coefficient. In this work, Cu₂O was obtained simply by reducing Benedict’s solution with glucose in an alkaline medium (pH 10.2 ± 0.2) at 65°C. The samples were synthesized by varying glucose content from 1 g to 7 g. The results showed a phase proportion variation between 95.56% and 99.50% of the Cu₂O phase. It was found that the changes in crystallite size, microstrains, particle size, and morphology are due to reaction times, which were influenced by the use of different glucose amounts. The use of a higher glucose amount in the synthesis favors a faster reaction, forming smaller crystallites with more microstrains. Lower glucose amount leads to a slower reaction giving the crystallites more time to grow, which relaxes the microstrains. When increasing glucose content, the obtained morphologies changed from cubes, irregular cubes, prismatic spheres, cauliflower‐like, to spherical shapes. The XPS spectra confirmed only the presence of chemical species such as Cu(I) and Cu(II), and chemical defects, such as oxygen vacancies (Vo), were detected in the samples. All samples presented a broad absorption range from 200 nm to 570 nm indistinctly of the morphology. The band gap showed an insignificant change from 2.04 eV to 2.09 eV when glucose was increased from 1 g to 7 g. The in-situ phase transformation study was analyzed from 25°C to 700°C. The results indicated a phase transition from Cu₂O to Cu and CuO when the temperature was above 280°C.

The anti-inflammatory effects of SGNs were evaluated by histology, DNA microarray and bioinformatic analyses, immunohistochemistry, flow cytometry, and tomography showing a reduction in joint damage and inflammation-related gene expression.

Gold nanoshells (GNSs), formed by a silica core surrounded by a gold shell, present a shift on their surface plasmon resonance (SPR) to the near-infrared (NIR) part of the electromagnetic spectrum when synthesized with specific dimensions. This chapter presents a simple method to prepare the nanoshells, a step-by-step characterization, as well as their absorbance spectrum. For the synthesis, silica spheres, with approximately 190 ± 5 nm in diameter, were prepared using the Stöber method and then functionalized with 3-aminopropyltriethoxysilane (APTES). The gold nanoparticles (GNPs), with a diameter of 7 ± 3 nm, were produced by the reduction of chloroauric acid. Then, the silica was seeded with the GNPs to later grow a gold shell with the help of Au(OH)4¯ ions and formaldehyde. UV-Vis spectroscopy results showed an increase of absorbance starting at 520 nm. It reached its maximum around 600 nm and kept absorbing all through 1200 nm. Transmission electron microscope (TEM) and scanning electron microscope (SEM) images suggest that the absorption peak movement coincided with the completion of the shell. Furthermore, when the sample was irradiated with an 820 nm wavelength/3.1 mW laser, its temperatures increased by 6.3°C in 2 min, showing its absorbance in the NIR.

Photothermal therapy (PTT) is an emerging minimally invasive approach for cancer treatment that relies on photothermal agents capable of efficiently converting near-infrared (NIR) light into localized heat. In this work, silica–gold nanostructures (SGNs) were synthesized and systematically evaluated to investigate how silica core size influences the photothermal response of the SGNs and optimize their performance as a photothermal agent. SGNs were synthesized with silica cores ranging from 54 to 244 nm in diameter and coated with gold nanoparticles of 4–10 nm in size, enabling controlled tuning of their localized surface plasmon resonance within the NIR region. The morphology and composition were characterized by SEM, TEM, and EDS; optical properties were analyzed by UV-Vis spectroscopy. The SGNs photothermal response low-power laser irradiation at 852 nm and 1310 nm and temperature changes were monitored using a thermographic camera. A maximum temperature increase of 7.1 °C was observed for SGNs with a silica core diameter of approximately 77 nm under the 852 nm laser irradiation. Numerical simulations of the absorption efficiency showed good agreement with experimental UV–Vis spectra and thermal measurements, revealing a size-dependent shift of the absorption toward longer wavelengths for larger nanostructures. These results demonstrate that the photothermal response of silica–gold nanostructures can be rationally tuned through the control of core size and gold growth parameters, providing a framework for the design of wavelength-matched photothermal agents for PTT applications.

In this work, thin films with a ZnO:Al/Ag/ZnO:Al multilayer structure were deposited by radio frequency (RF) and pulsed DC sources in a magnetron sputtering system on glass substrates at 50 °C with different deposition times of the Ag layer. The results showed that the thin films' properties improved with increasing the deposition time of the silver metallic interlayer and with thermal treatment at 300 °C for one hour. The highest average transmittance in the visible range was 89 %. The best values of resistivity and conductivity were 10-4 Ω·cm and 103 Ω-1cm-1, respectively. Finally, the XRD patterns showed that with an increase in the Ag layer's deposition time, the plane's peak (111) belonging to the Ag plane was observed.