Highly sensitive and selective fluorescence sensing and imaging of Fe 3+ based on a novel nitrogen doped graphene quantum dots

• Published in: Luminescence (Chichester, England) England), 2021-11, Vol.36 (7), p.1592-1599
• Main Authors: Wu, Dongming, Qu, Chaojie, Wang, Jizhong, Yang, Ran, Qu, Lingbo
• Format: Article
• Language: English
• ISSN: 1522-7235; 1522-7243
• DOI: 10.1002/bio.4062

A novel nitrogen doped graphene quantum dots (N-GQDs) with a green fluorescence emission was synthesized through microwave method using citric acid and semicarbazide hydrochloride as reactants. The as-synthesized N-GQDs exhibits good stability, excellent water solubility and negligible cytotoxicity. Due to the intermolecular charge transfer, ferric ion (Fe ) has a strong quenching effect on the N-GQDs. The fluorescence quenching has a linear relationship with the concentration of Fe in the range of 0.02-12 μM. The detection limit was 1.43 nM. What's more, it's worth mentioning that the obtained N-GQDs showed high selectivity and sensitivity towards Fe . Under the optimum conditions, 10-times copper ions and 100-times other metal ions had no influence on the detection of Fe (0.8 μM), which indicates a higher sensitivity than that of the reported methods. Due to their excellent properties, the obtained N-GQDs was successfully applied for sensing and imaging Fe in water samples and HeLa cells.