Biofilm Inhibition by Laser-Induced Graphene: Impact of Surface Texture on Rod-Shaped <i>E. coli</i> and Coccus-Shaped <i>Staphylococcus</i>

Biofilm formation poses persistent challenges across various industrial sectors, such as food, marine, and membrane industries, often leading to reduced system performance. An antibiofilm strategy using nanotextured surfaces, such as laser-induced graphene (LIG), has emerged as a potent antibiofilm surface, particularly against rod-shaped bacteria. However, biofilms in nature consist of diverse bacterial species, necessitating a thorough evaluation of LIG efficacy against various bacterial species. Therefore, this study comprehensively analyzed the antibiofilm potential of LIG nanofibers fabricated on polyether sulfone (PES) film. The study focused on two bacterial species with distinct morphologies: rod-shaped <i>Escherichia coli</i> and coccus-shaped <i>Staphylococcus epidermidis</i>. The antibiofilm potential of LIG was studied under extended biofilm-promoting conditions for 10 days. The surface with crushed LIG nanofibers (C-LIG) showed substantial biofilm accumulation, with live biomass of ∼7 μm³ μm^-2 for <i>E. coli</i> and ∼6 μm³ μm^-2 for <i>S. epidermidis</i>. In contrast, LIG nanofibers prevented biofilm formation for both species. We also observed LIG-induced cell size alteration for rod- and coccus-shaped bacterial cells. Notably, there was an ∼39% reduction in <i>E. coli</i> cell size compared to the control PES, resulting in a morphological shift to an ovoid shape, likely due to activation of the General Stress Response (GSR). However, <i>S. epidermidis</i> did not exhibit any morphological changes. We also provided the first evidence that <i>E. coli</i> cells exposed to LIG-induced stress regained their original size when cultured in a stress-free environment, indicating these morphological changes were reversible. Further, whole-genome sequencing supported this observation by showing no single nucleotide polymorphism, indicating no permanent genetic alterations in stressed <i>E. coli</i> cells. Overall results showed that LIG nanofibers disrupted biofilm formation in both bacterial species. Thus, our findings highlight the potential of LIG as a robust antibiofilm surface that offers broader applicability in biofilm-prone environments.