Surface Mesoscopic Characterization and Analysis of Nanosecond-Laser-Processed Molybdenum for the Optimization of Antibacterial Performance

Molybdenum has gained attention as a promising biomedical material due to its excellent mechanical properties and inherent antimicrobial activity. However, challenges remain in developing facile fabrication methods and further enhancing its antimicrobial efficacy. This study pioneers the investigation of biofilm inhibition by laser-treated molybdenum sheets against Pseudomonas aeruginosa (ATCC27853) and Staphylococcus aureus (ATCC25923). The experimental results demonstrate that nanosecond-pulsed laser processing significantly suppresses biofilm formation, reducing the minimum optical density (OD) values by 25.3% and 64.9% for the two bacterial strains, respectively. The laser treatment modifies the surface morphology of molybdenum by eliminating defects, reducing the effective contact area, and lowering hydrophobicity. Additionally, localized laser heating induces the formation of MoO₃ on the surface, which reacts with water to generate molybdic acid—a key contributor to antibacterial activity. These findings highlight nanosecond-pulsed laser processing as a cost-effective, scalable surface-modification strategy for medical-grade molybdenum. This approach holds significant potential for broadening the antimicrobial applications of molybdenum-based biomedical devices and implants.