Rapid Detection of Bacteria by Carbon Quantum Dots

This work demonstrated a fluorescence measurement method for rapid detection of bacteria and their counting by using water-soluble carbon quantum dots (CQDs) as a fluorescence marker while sewage water bacteria were detection target bacteria. Highly luminescent water-soluble CQDs were prepared by carbonizing waste part of rice straw materials in a furnace under in-sufficient air flow. Bacteria in a LB media with <100 nm of water soluble CQDs were cultured for 30–40 minutes. The multi colored bacterial cell images were obtained by using fluorescence microscopy. Our results showed that CQDs prepared in water phase were highly luminescent, stable, and successfully conjugated with bacterial cell membrane only. Also we could count the total number of bacteria within a shortest time from any sample of environment.