Seeking brightness from nature: controlled synthesis of multicolor fluorescent carbon dots from biomass.

Fluorescent carbon dots (CDs) exhibit broad application prospects in multiple fields, such as food testing and biomedicine, owing to their abundant raw material sources, excellent biocompatibility, and superior fluorescence properties. However, the diversity of biomass raw materials poses challenges to the controllable preparation of CDs, significantly limiting their large-scale production and practical application. In this study, bamboo leaves were employed as a single precursor, and a one-step solvothermal method was adopted. By regulating the reaction temperature, precise synthesis of multi-band fluorescent CDs was achieved, successfully yielding red-fluorescent R-CDs (emitting at 680 nm), pink dual-emission fluorescent P-CDs (emitting at 480 nm/680 nm), and blue-fluorescent B-CDs (emitting at 450 nm). All synthesized CDs possess excellent optical properties, characterized by high fluorescence intensity and narrow emission bands. Notably, B-CDs demonstrate remarkable specific recognition toward tartrazine through the synergistic effect of internal filtering and static quenching. This study provides a simple and efficient technical approach for the controlled synthesis of biomass-derived CDs, further expanding their application potential in food detection, chemical analysis, and biomedicine.