Researchers developed a surface that kills bacteria on contact by covalently attaching poly(4-vinyl-N-alkylpyridinium bromide) to glass slides. This surface effectively killed up to 94% of Staphylococcus aureus cells, and even more of other bacteria like Staphylococcus epidermidis, Pseudomonas aeruginosa, and Escherichia coli. The antibacterial effect was achieved by modifying the glass surface with long, flexible polycationic chains that could penetrate bacterial cell walls. The surface was tested against various materials, and it was found that only the modified glass surfaces significantly reduced the number of viable bacteria, while common materials like ceramics, plastics, metals, and wood did not. The surface was created using two methods, both of which resulted in highly effective antibacterial surfaces. The surface was also shown to not leach antibacterial agents, indicating that bacteria were killed on contact. The study highlights the potential of this surface modification for use in everyday objects to prevent bacterial infections. The research was supported by financial grants from the Ministry of Economic Affairs and the National Institutes of Health.Researchers developed a surface that kills bacteria on contact by covalently attaching poly(4-vinyl-N-alkylpyridinium bromide) to glass slides. This surface effectively killed up to 94% of Staphylococcus aureus cells, and even more of other bacteria like Staphylococcus epidermidis, Pseudomonas aeruginosa, and Escherichia coli. The antibacterial effect was achieved by modifying the glass surface with long, flexible polycationic chains that could penetrate bacterial cell walls. The surface was tested against various materials, and it was found that only the modified glass surfaces significantly reduced the number of viable bacteria, while common materials like ceramics, plastics, metals, and wood did not. The surface was created using two methods, both of which resulted in highly effective antibacterial surfaces. The surface was also shown to not leach antibacterial agents, indicating that bacteria were killed on contact. The study highlights the potential of this surface modification for use in everyday objects to prevent bacterial infections. The research was supported by financial grants from the Ministry of Economic Affairs and the National Institutes of Health.