Molybdenum Disulfide Surfaces to Reduce and Biofilm Formation.

The reduction of bacteria and biofilm formation is important when designing surfaces for use in industry. Molybdenum disulfide surfaces (MoS) were produced using MoS particle (MoS) sizes of 90 nm, 2 μm, and 6 μm containing MoS concentrations of 5%, 10%, 15%, and 20%. These were tested to determine the efficacy of the MoS to impede bacterial retention and biofilm formation of two different types of bacteria, and . The MoS were characterized using Fourier transform infrared spectroscopy, ion-coupled plasma atomic emission spectroscopy, scanning electron microscopy, optical profilometry, and water contact angles. The MoS made with the smaller 90 nm MoS sizes demonstrated smaller topographical-shaped features. As the size of the incorporated MoS increased, the MoS demonstrated wider surface features, and they were less wettable. The increase in MoS concentration within the MoS groups did not affect the surface topography but did increase wettability. However, the increase in MoS size increased both the surface topography and wettability. The MoS with the smaller topographical-shaped features influenced the retention of the bacteria. Increased MoS topography and wettability resulted in the greatest reduction in bacterial retention, and the bacteria became more heterogeneously dispersed and less clustered across the surfaces. The surfaces that exhibited decreased bacterial retention (largest particle sizes, largest features, greatest roughness, and most wettable) resulted in decreased biofilm formation. Cytotoxicity testing of the surface using cell viability demonstrated that the MoS were not toxic against HK-2 cells at MoS sizes of 90 nm and 2 μm. This work demonstrated that individual surface variables (MoS topographic shape and roughness, MoS size, and concentration) decreased bacterial loading on the surfaces, which then decreased biofilm formation. By optimizing MoS properties, it was possible to impede bacterial retention and subsequent biofilm formation.