With antibiotic resistance on the rise, scientists have been looking for alternative ways to fend off bacterial infections. A novel antibacterial strategy using quantum dots made of graphene could take antibiotics completely out of the equation. Under low-intensity blue light, the quantum dots were able to eliminate over 99.9% of S. aureus and E. coli bacteria, including strains resistant to multiple types of antibiotics. Over the past three decades, very few new antibiotics have been discovered and approved, and most are only slight variations of existing drugs. This has left the world’s population increasingly vulnerable to the rapid rise of antibiotic resistance. “The World Health Organization (WHO) warned about the impending ‘post-antibiotic’ era, where even minor injuries and ordinary bacterial infections may prove fatal,” writes Sedat Nizamoğlu, professor at Koç University in Istanbul. “This phenomenon is a direct consequence of the growing prevalence of antibiotic resistance among bacteria.” Facing this growing crisis, Nizamoğlu and colleagues decided to take a different approach. Instead of searching for new antibiotics, they turned to a quantum-based solution to fight antibiotic-resistant bacteria. Quantum killers Quantum dots are structures so small—just about a few dozen atoms wide—that they are able to trap electrons inside. This allows them to absorb and emit light at very specific wavelengths, making quantum dots popular across a wide range of applications including screen displays, solar panels, and quantum computers. In this case, light emitted by the quantum dots reacts with oxygen to create highly reactive molecules that are toxic to bacteria. Known as reactive oxygen species, these molecules damage the cell wall that protects bacteria and disrupt their antioxidant defenses, making them effective against a broad range of bacteria. While the idea of using quantum dots to kill bacteria is not entirely new, earlier attempts have faced some major limitations. A