Prominent antibacterial effect of sub 5 nm Cu nanoparticles/MoS 2 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 (MoS ₂ ) 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 MoS ₂ raised some concerns. In this paper, we successfully realized a uniform decoration of copper nanoparticles (CuNPs) on surface of MoS ₂ nanosheets, and the size of CuNPs could be controlled below 5 nm. Under 5 min irradiation of 660 nm visible light, the synthesized CuNPs/MoS ₂ 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 MoS ₂ ), while the bactericidal effect could last for at least 6 h. The synergism of photodynamic generated hydroxyl radical (·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/MoS ₂ . Our findings provided new insights into the development of two-dimensional antibacterial nanomaterials of high cost performance.
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