Antibacterial Properties of Citric Acid/β-Alanine Carbon Dots against Gram-Negative Bacteria

• Main Authors: Anju Pandey, Asmita Devkota, Zeinab Yadegari, Korsi Dumenyo, Ali Taheri
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Nanomaterials
• Subjects: antimicrobial; multiple drug resistance; MDR; carbon dots
• Online Access: https://www.mdpi.com/2079-4991/11/8/2012

While multi-drug resistance in bacteria is an emerging concern in public health, using carbon dots (CDs) as a new source of antimicrobial activity is gaining popularity due to their antimicrobial and non-toxic properties. Here we prepared carbon dots from citric acid and β-alanine and demonstrated their ability to inhibit the growth of diverse groups of Gram-negative bacteria, including <i>E. coli</i>, <i>Salmonella</i>, <i>Pseudomonas</i>, <i>Agrobacterium</i>, and <i>Pectobacterium</i> species. Carbon dots were prepared using a one-pot, three-minute synthesis process in a commercial microwave oven (700 W). The antibacterial activity of these CDs was studied using the well-diffusion method, and their minimal inhibitory concentration was determined by exposing bacterial cells for 20 h to different concentrations of CDs ranging from 0.5 to 10 mg/mL. Our finding indicates that these CDs can be an effective alternative to commercially available antibiotics. We also demonstrated the minimum incubation time required for complete inhibition of bacterial growth, which varied depending on bacterial species. With 15-min incubation time, <i>A. tumefaciens</i> and <i>P. aeruginosa</i> were the most sensitive strains, whereas <i>E. coli</i> and <i>S. enterica</i> were the most resistant bacterial strains requiring over 20 h incubation with CDs.