Synthesis of sulfur-doped carbon quantum dots from Solanum nigrum for ciprofloxacin detection in yogurt samples and antibacterial activity

for each bacterium, respectively. Mechanistic investigations indicated that the positively charged S-CQDs electrostatically interacted with negatively charged bacterial membranes, disrupting membrane integrity and ultimately leading to bacterial cell death. This work establishes a novel approach for developing multifunctional S-CQDs, highlighting their promising applications in clinical diagnostics, environmental monitoring and antimicrobial therapies.