Prominent antibacterial effect of sub 5 nm Cu nanoparticles/MoS2 composite under visible light

Achieving an efficient and inexpensive bactericidal effect is a key point for the design of antibacterial agent. Recent advances have proved molybdenum disulfide (MoS2) as a promising platform for antimicrobial applications, while the combination of metal nanoparticle would promote the antibacterial efficiency. Nevertheless, the dispersivity, cheapness and safety of metal nanoparticle loaded on MoS2 raised some concerns. In this paper, we successfully realized a uniform decoration of copper nanoparticles (CuNPs) on surface of MoS2 nanosheets, and the size of CuNPs could be controlled below 5 nm. Under 5 min irradiation of 660 nm visible light, the synthesized CuNPs/MoS2 composite demonstrated superior antibacterial performances (almost 100% bacterial killed) towards both Gram-negative E. coli and Gram-positive S. aureus over the single component (Cu or MoS2), while the bactericidal effect could last for at least 6 h. The synergism of photodynamic generated hydroxyl radical (center dot OH), oxidative stress without reactive oxygen species production and the release of Cu ions was considered as the mechanism for the antibacterial properties of CuNPs/MoS2. Our findings provided new insights into the development of two-dimensional antibacterial nanomaterials of high cost performance.

Automated summary

This study successfully decorated copper nanoparticles on molybdenum disulfide nanosheets, forming CuNPs/MoS2 composite with superior antibacterial performances. The synthesized composite demonstrated almost 100% bacterial kill towards both Gram-negative E. coli and Gram-positive S. aureus, and the bactericidal effect could last for at least 6 hours. The antibacterial properties of CuNPs/MoS2 were attributed to the synergism of photodynamic generated hydroxyl radical, oxidative stress without reactive oxygen species production and the release of Cu ions.