Synthesis and Chromatographic Isolation of Blue, Green, and Orange Emissive Carbon Dots with High Quantum Yields from Taraxacum

Carbon dots (CDs) have emerged as a novel class of fluorescent nanomaterials with superior optical properties and biocompatibility compared to traditional quantum dots. This study demonstrates a facile approach for synthesizing high quantum yield tricolor CDs from the natural precursor dandelion via a one-step solvothermal treatment. Chromatographic separation successfully yielded blue, green, and orange emissive CDs with emission peaks at 481 nm, 530 nm, and 587 nm respectively. Structural and optical characterization revealed the CDs possess excellent photostability, salt resistance, and thermal stability, alongside high quantum yields, measured at 43.8%, 32.9%, and 48.1% for B-CDs, G-CDs, and O-CDs, respectively. Taking advantage of the unique properties of the tricolor CDs, their application in analytical sensing was explored using metal ion detection. The CDs displayed selective quenching responses towards Fe3+, Pb2+, and Sn4+ respectively, with strong anti-interference capabilities. This work provides a sustainable and efficient strategy for producing high-performance multicolor CDs, holding significant implications for reducing the synthesis cost of carbon dots and expanding their application spectrum.