Lignin-based fluorescence-switchable graphene quantum dots for Fe3+ and ascorbic acid detection

Lingyan Zhu, Dongbing Li, Heng Lu, Shangkun Zhang, Hao Gao

Research output: Journal PublicationArticlepeer-review

28 Citations (Scopus)


The synthesis of lignin-based graphene quantum dots (GQDs) with excellent fluorescence stability, quantum yield, and biocompatibility for sensitive and selective detection of Fe3+ and ascorbic acid (AA) has remained a challenging endeavor. Using an acidolysis process with 17.5% nitric acid followed by hydrothermal treatment at 200 °C, this study provided an improved synthesis route for the production of high-quality GQDs from alkali lignin. The nitrogen-doped GQDs exhibit remarkable fluorescence stability under a wide range of pH (3–10), duration (1–12 h), and [NaCl] (0–1000 mM) conditions, and have a high quantum yield of 28%. The GQDs or GQDs/Fe3+ sensing systems ([GQDs] at 50 mg L−1, [Fe3+] at 500 μmol L−1, and UV excitation at 370 nm) for fluorescence sensing of Fe3+ or AA have excellent sensitivity, selectivity, and reproducibility. For Fe3+ and AA, the limit of detection is 1.49 and 1.62 μmol L−1, respectively. Mechanism investigation shows that photoluminescence quenching is caused by the formation of GQDs-Fe3+ complexes, whereas fluorescence recovery is due to Fe3+ reduction by AA.

Original languageEnglish
Pages (from-to)254-263
Number of pages10
JournalInternational Journal of Biological Macromolecules
Publication statusPublished - 1 Jan 2022
Externally publishedYes


  • Alkali lignin
  • Fluorescence sensing
  • Graphene quantum dots

ASJC Scopus subject areas

  • Structural Biology
  • Biochemistry
  • Molecular Biology


Dive into the research topics of 'Lignin-based fluorescence-switchable graphene quantum dots for Fe3+ and ascorbic acid detection'. Together they form a unique fingerprint.

Cite this