Application of carbon dots synthesized with amino acid as precursor in the detection of phloroglucinol

• Published in: Microchemical journal 2024-09, Vol.204, p.111099, Article 111099
• Main Authors: Wang, Min, Hou, Aiying, Yang, Dou, Shao, Tong, Li, Rui, Hong, Min, Yue, Qiaoli
• Format: Article
• Language: English
• Subjects: Amino acid; Carbon dots; Fluorescence; Phloroglucinol
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/j.microc.2024.111099

[Display omitted] •N-doped CDs with bright blue fluorescence were applied in PG detection.•The fluorescence of CDs was quenched by PG due to the hydrogen bond.•The LOD of PG is 12 nM which is lower than those of other methods.•PG was successfully measured in lake water and tap water samples. Nitrogen doped carbon dots (CDs) were successfully applied in the detection of phloroglucinol. CDs were hydrothermally synthesized from L-phenylalanine (L-phe) and L-leucine (L-leu) in alkaline aqueous solution. The morphology, size and functional groups of CDs were characterized by transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The average size of CDs was 4.26 ± 1.77 nm. The main elements of CDs were C, N, O and functional groups were carboxyl, hydroxyl, pyridine and amino groups. CDs showed bright blue fluorescence with the quantum yield (QY) at 12.82 % (λex = 337 nm and λem = 437 nm). In the presence of phloroglucinol (PG), however, the fluorescence of CDs was quenched significantly. It could be ascribed from hydrogen bonds formed between PG and functional groups on the surface of CDs. There was a good linear response between the fluorescence quenching of CDs and the concentration of PG in the range of 0.5–150 μM with the limit of detection (LOD) at 12 nM. The strategy can be used to detect PG qualitatively and quantitatively with the advantages of low cost, high sensitivity, fast response and high specificity.