Selective eradication of pathogenic bacteria using amine-modified corn-straw carbon dots

The rise of antimicrobial resistance and the ecological harm inflicted by broad-spectrum disinfectants underscore the urgent need for species-specific strategies that eradicate pathogenic bacteria without disrupting beneficial microbial communities. Staphylococcus aureus thrives in diverse aquatic environments across wide temperature ranges, posing persistent risks to human health and exacerbating resistance challenges, yet existing agents lack the precision to target this pathogen selectively. Here we show that triethylenetetramine-functionalized carbon dots, derived from corn straw biomass via one-step hydrothermal synthesis, exhibit intrinsic oxidase-like activity that selectively eliminates S. aureus . These nanomaterials achieve complete bactericidal efficacy (100%) against S. aureus at 50 μg mL −1 within 1 h at 37 °C, retaining robust activity (80%) even at 4 °C, through synergistic preferential binding to cell-wall polysaccharides—facilitated by retained biomass cellulose moieties—combined with membrane disruption and generation of superoxide radicals (·O 2 − ) and singlet oxygen ( 1 O 2 ). This selectivity spares Bacillus subtilis and Gram-negative species such as Escherichia coli and Pseudomonas aeruginosa , owing to differences in cell-wall architecture and reduced affinity. Amine chain length tunes the oxidase-mimicking potency, enabling oxygen-dependent reactive oxygen species production without external stimuli. By upcycling abundant agricultural waste into rapidly photodegradable (within 11 days under visible light) precision disinfectants, this approach provides a sustainable way for ecologically compatible pathogen control, advancing rational design principles for next-generation nano-antimicrobials. • Amine-modified carbon dots from corn straw selectively kill S. aureus while sparing probiotics like B. subtilis. • TETA-functionalized CDs achieve 100% bactericidal rate against S. aureus at 50 μg mL −1 within 1 h. • Oxidase-like activity enables ROS generation and membrane disruption, effective even at 4 °C. • Converts biomass waste into eco-friendly nanomaterials for targeted water disinfection. • Preserves aquatic microbial communities, advancing sustainable antibacterial strategies.