A high-yield and versatile method for the synthesis of carbon dots for bioimaging applications. Issue 10 (17th February 2017)

• Record Type: Journal Article
• Authors: Li, Liping; Lu, Chunxiang; Li, Sijin; Liu, Shijie; Wang, Lingjie; Cai, Wenwen; Xu, Wen; Yang, Xi; Liu, Yaodong; Zhang, Ruiping
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 10(2017)
• Page Start: 1935
• Page End: 1942
• Publication Date: 2017-02-17
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Biomedical materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c6tb03003c
• Languages: English
• ISSNs: 2050-750X

Abstract

Abstract : High yield carbon dots (CDs) were synthesized on a large scale by a facile and versatile molten-salt method, using different precursors. The CDs not only exhibit efficient labelling ability in vitro, but could be chelated with gadolinum ions to constrcut Gd-CDs for dual-mode magnetic resonance and fluorescence imaging. Abstract : A facile and versatile molten-salt method was developed to prepare hydrosoluble carbon dots (CDs) from various precursors, in high yields and on a large scale. Citric acid-based CDs (CA-CDs) were obtained in a maximum yield of 39.6% and exhibited a high fluorescence quantum yield of 20.8% without any passivation. The CA-CDs showed little cytotoxicity even at a concentration as high as 800 μg mL −1 . In addition, CA-CDs could be used as multicolour fluorescence imaging agents in vitro with blue, green, and red fluorescence emissions at excitation wavelengths of 405, 488, and 543 nm, respectively. Moreover, the CA-CDs could be chelated with gadolinium ions (Gd 3+ ) to construct Gd-CA-CDs for dual-mode magnetic resonance and fluorescence imaging. The Gd-CA-CDs showed good water dispersibility, excellent biocompatibility, a strong fluorescence quantum yield of 13.1%, and a high magnetic resonance relaxivity of 22.45 mM −1 s −1 . The molten-salt method was demonstrated to be applicable to other precursors, such as sodium lignosulphonate, sucrose, glucose, and p -phenylenediamine, and the maximum yield of the four as-prepared CDs was as high as 66.7%, which is much higher than the value reported in previous studies. This study proves that the molten-salt synthesis is a versatile method to obtain CDs in high yields, which will promote the application of CDs in the field of bioimaging.