摘要
The antibacterial activity of copper is well-known from an ancient civilization, however, its biocidal mechanism has not been necessarily elucidated. Notwithstanding up to now, mainly 4 processes have been proposed. Among them, it is cleared that 4 kinds of reactive oxygen species (ROS): hydroxyl radical ·OH, hydrogen per oxide H<sub>2</sub>O<sub>2</sub>, superoxide anion ·O<sup>-</sup>2</sub></sub> and singlet oxygen <sup>1</sup>O<sub>2</sub>, play an important role for contact-killing of bacteria, viruses and fungi. In this paper, generation of ROS on the surfaces of copper plates heated from room temperature to 673 K for 4.2 × 10<sup>2</sup> s in air, was investigated using the chemiluminescence. ROS have been evaluated by selecting the most suitable scavengers, such as 2-propanol for ·OH, sodium pyruvate for H<sub>2</sub>O<sub>2</sub>, nitro blue tetrazolium for ·O<sup>-</sup>2</sub></sub>, and sodium azide NaN<sub>3</sub> for <sup>1</sup>O<sub>2</sub>. At the same time the outermost surface of copper, on which thin film of cuprous oxide Cu<sub>2</sub>O was first formed and then cupric oxide CuO was laminated on Cu<sub>2</sub>O, was examined by thin-film XRD and TEM analysis to estimate the amounts and kinds of copper oxides. It was found that the most amounts of ROS were obtained for the 573 K-heated Cu plate and they were composed of ·OH, H<sub>2</sub>O<sub>2</sub>, and ·O<sup>-</sup>2.</sub></sub>.
The antibacterial activity of copper is well-known from an ancient civilization, however, its biocidal mechanism has not been necessarily elucidated. Notwithstanding up to now, mainly 4 processes have been proposed. Among them, it is cleared that 4 kinds of reactive oxygen species (ROS): hydroxyl radical ·OH, hydrogen per oxide H<sub>2</sub>O<sub>2</sub>, superoxide anion ·O<sup>-</sup>2</sub></sub> and singlet oxygen <sup>1</sup>O<sub>2</sub>, play an important role for contact-killing of bacteria, viruses and fungi. In this paper, generation of ROS on the surfaces of copper plates heated from room temperature to 673 K for 4.2 × 10<sup>2</sup> s in air, was investigated using the chemiluminescence. ROS have been evaluated by selecting the most suitable scavengers, such as 2-propanol for ·OH, sodium pyruvate for H<sub>2</sub>O<sub>2</sub>, nitro blue tetrazolium for ·O<sup>-</sup>2</sub></sub>, and sodium azide NaN<sub>3</sub> for <sup>1</sup>O<sub>2</sub>. At the same time the outermost surface of copper, on which thin film of cuprous oxide Cu<sub>2</sub>O was first formed and then cupric oxide CuO was laminated on Cu<sub>2</sub>O, was examined by thin-film XRD and TEM analysis to estimate the amounts and kinds of copper oxides. It was found that the most amounts of ROS were obtained for the 573 K-heated Cu plate and they were composed of ·OH, H<sub>2</sub>O<sub>2</sub>, and ·O<sup>-</sup>2.</sub></sub>.
作者
Ken Hirota
Hiroya Tanaka
Taika Maeda
Kazuhiko Tsukagoshi
Hiroshi Kawakami
Takashi Ozawa
Masahiko Wada
Ken Hirota;Hiroya Tanaka;Taika Maeda;Kazuhiko Tsukagoshi;Hiroshi Kawakami;Takashi Ozawa;Masahiko Wada(Research Center of Bio-Micro-Fluidic Science, Doshisha University, Kyoto, Japan;Department of Chemical Engineering and Materials Science, Faculty of Science & Engineering, Doshisha University, Kyoto, Japan;Graduate School of Engineering, College of Engineering, Osaka Metropolitan University, Osaka, Japan;Japan Copper Development Association, Tokyo, Japan)
