Hierarchical Micro/Mesoporous Copper Structure with Enhanced Antimicrobial Property via Laser Surface Texturing
Vidhya Selvamani, Amin Zareei, Ahmed Elkashif, Murali Kannan Maruthamuthu, Shirisha Chittiboyina, Davide Delisi, Zheng Li, Lirong Cai, Vilas G. Pol, Mohamed N. Seleem, Rahim Rahimi
Abstract
Abstract Copper (Cu) and its alloys have been shown to eradicate a wide range of multidrug‐resistant microbes upon direct contact. In this study, a facile one‐step laser texturing (LT) process is demonstrated to effectively enhance the bactericidal properties of copper surfaces via concurrent selective modification of surface topography and chemistry of laser textured copper (LT‐Cu). Surface morphology and elemental composition are analyzed via field emission scanning electron microscopy (FE‐SEM), energy‐dispersive X‐ray spectroscopy (EDX), and Raman spectroscopy. Surface area and pore size of LT‐Cu is determined by Barrett–Joyner–Halenda (BJH) and Brunauer–Emmett–Teller (BET) analysis. It reveals direct formation of mesoporous structures with higher surface oxide (Cu 2 O and CuO), which provide a highly stable superhydrophilic property to the LT‐Cu surfaces. The antibacterial properties of LT‐Cu are tested against pathogenic bacterial strains with different concentrations including Pseudomonas aeruginosa , and methicillin‐resistant Staphylococcus aureus (MRSA USA300) at 10 5 CFU mL −1 , and Escherichia coli and Staphylococcus aureus at high bacterial concentrations of 10 8 CFU mL −1 using standard contact killing tests. The analysis shows that LT‐Cu needs 40, 90, 60, and 120 min to completely eradicate the respective bacterial strain. The LT‐Cu causes membrane damage to the bacterial cells immediately after exposure. Furthermore, the biocompatibility of LT‐Cu is investigated by in vitro immune‐staining assays with mammary stromal fibroblasts and T4‐2 cells.