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Metallic nanostructures are applied in many fields, including photonics and plasmonics, due to their ability to absorb or emit light at frequencies which depend on their size and shape. It was recently shown that irradiation by a focused electron beam can promote the growth of nanostructures on metal surfaces and the height of these structures depends on the duration of the irradiation and the material of the surface. However, the effects on growth dynamics of numerous irradiation parameters, such as beam current or angle of incidence, have not yet been studied in detail. We explore the effects of focusing, angle of incidence, and current of the electron beam on the size and shape of the resulting structures on an Ag surface. In addition, we investigate how the nitrogen plasma cleaning procedure of a vacuum chamber can affect the growth of these structures. A beam current of around 40 pA resulted in the fastest structure growth rate. By increasing the beam diameter and angle of incidence the growth rate decreased; however, by raising the beam focus up to 5–6 μm above the surface the growth rate increased. Vacuum chamber cleaning reduced structure growth rate for a few hours. These findings can help to better control and optimise the growth of nanostructures on metal surfaces undergoing irradiation by a focused electron beam.

This article describes the synthesis of nanostructured copper oxide on copper wires and its application for the detection of hydrogen peroxide. Copper oxide petal nanostructures were obtained by a one-step hydrothermal oxidation method. The resulting coating is uniform and dense and shows good adhesion to the wire surface. Structure, surface, and composition of the obtained samples were studied using field-emission scanning electron microscopy along with energy-dispersive spectroscopy and X-ray diffractometry. The resulting nanostructured samples were used for electrochemical determination of the H2O2 content in a 0.1 M NaOH buffer solution using cyclic voltammetry, differential pulse voltammetry, and i–t measurements. A good linear relationship between the peak current and the concentration of H2O2 in the range from 10 to 1800 μM was obtained. The sensitivity of the obtained CuO electrode is 439.19 μA·mM−1. The calculated limit of detection is 1.34 μM, assuming a signal-to-noise ratio of 3. The investigation of the system for sensitivity to interference showed that the most common interfering substances, that is, ascorbic acid, uric acid, dopamine, NaCl, glucose, and acetaminophen, do not affect the electrochemical response. The real milk sample test showed a high recovery rate (more than 95%). According to the obtained results, this sensor is suitable for practical use for the qualitative detection of H2O2 in real samples, as well as for the quantitative determination of its concentration.