Bacteria-derived fluorescent carbon dots for microbial live/dead differentiation.

Area of Science:

• Biotechnology
• Materials Science
• Microbiology

Background:

• Microbial viability assessment is crucial for pathogen detection, infectious disease treatment, and antimicrobial drug development.
• Conventional viability dyes like propidium iodide (PI) exhibit cytotoxicity, poor photostability, and high costs, limiting their application.
• There is a need for advanced, cost-effective, and reliable methods for microbial live/dead differentiation.

Purpose of the Study:

• To synthesize fluorescent carbon dots (CDs) from bacteria for microbial viability assessment.
• To evaluate the selectivity and advantages of these novel CDs compared to conventional dyes.
• To explore the potential of bacteria-derived CDs for broader biomedical applications.

Main Methods:

• One-step hydrothermal carbonization of bacteria to synthesize fluorescent carbon dots (CDs).
• Characterization of CDs' surface charge (zeta potential) and size.
• Assessment of selective staining of dead microbial cells (bacteria and fungi) versus live cells.
• Comparative analysis of CDs' properties (cytotoxicity, photostability, selectivity) against propidium iodide (PI).

Main Results:

• Successfully synthesized fluorescent carbon dots (CDs) from bacteria via a simple, eco-friendly hydrothermal method.
• The synthesized CDs exhibit a highly negative surface charge (around -42 mV) and suitable size for selective staining of dead microbial cells.
• CDs demonstrated low cytotoxicity, excellent photostability, high selectivity, and multicolor imaging ability, outperforming the commercial dye PI.
• The developed CDs effectively differentiate between live and dead microbial cells.

Conclusions:

• Bacteria-derived fluorescent carbon dots offer a novel, efficient, and cost-effective solution for microbial viability assessment.
• These CDs present significant advantages over traditional viability dyes, including enhanced performance and reduced cytotoxicity.
• The simple, scalable synthesis method makes these CDs highly suitable for large-scale production and diverse biomedical applications, including pathogen detection and antimicrobial research.