Nanoengineered Carbon Dots for Enhanced Antibacterial Response and Sensitive Bacterial Sensing

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Carbon dots (CDs) are increasingly relevant in various applications.
• Developing CDs with enhanced antibacterial activity and sensitive pathogen identification is of significant interest.
• Nitrogen-doped carbon dots (N-CDs) offer potential improvements over pristine CDs.

Purpose of the Study:

• To synthesize CDs and N-CDs using an efficient microwave method.
• To evaluate the antibacterial properties and pathogen detection capabilities of CDs and N-CDs.
• To investigate the potential of these nanomaterials as nanosensors for food safety.

Main Methods:

• Microwave-assisted synthesis of CDs and N-CDs.
• Characterization of nanomaterial size and stability.
• Antibacterial activity assays (inhibition zone, bacterial growth).
• Quantitative detection of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) using regression calibration curves.
• Nanosensing application in orange juice with recovery tests.

Main Results:

• CDs and N-CDs were synthesized rapidly, economically, and stably for up to 3 months.
• N-CDs demonstrated superior antibacterial properties compared to CDs.
• High correlation coefficients (r² > 0.99) were achieved for quantitative bacterial detection.
• Nanosensors in orange juice showed acceptable recovery rates (<4% RSD), confirming viability.

Conclusions:

• The microwave method provides an efficient route to stable CDs and N-CDs.
• N-CDs possess enhanced antibacterial activity and are effective for sensitive bacterial detection.
• The developed nanosensor strategy is viable for detecting S. aureus and E. coli in food matrices like orange juice.