Fluorescent N-doped carbon dots from bacterial cellulose for highly sensitive bacterial detection

Carbon dots have good dispersion capability, strong visible fluorescence, low toxicity, and photo-induced accepting and donating abilities. Carbon dots were obtained from biomass bacterial cellulose (BC) via one-step hydrothermal carbonization. Effects of hydrothermal time and temperature on the microstructure, fluorescence, and excitation wavelength dependent photoluminescence (PL) behavior were explored for the prepared carbon dots. The results showed that the carbon dots obtained directly from the BC (C dots) had small particle sizes (2.0 to 3.0 nm) and green luminescence behavior. Conversely, the N-doped carbon dots (N-C dots) exhibited more uniform and smaller particle sizes (approximately 1.0 nm), strong blue luminescence, acceptable fluorescence lifetime, and good stability in a wide range of pH values (2.0 to 10.0). Thus, carbon dots could serve as a fluorescent material used in high performance optical cellular imaging and highly sensitive bacterial detection.