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The Effect of Reaction Temperature on Fluorescence
Properties of Carbon Dots
K Yang, C L Wang, S Ding, F Li and F Tian
*
Institute of Medical Equipment, Academy of Military Medical Sciences, Tianjin,
300161, PR China.
Corresponding author and e-mail: F Tian, tianfeng62037@163.com
Abstract. In the present study, highly fluorescence carbon dots (CDs) were synthesized by
one step hydrotherma l method using citric acid (CA) as carbon source and 1,2-
ethylenediamine (EDA) as passivation agent. The samples of CDs under different reaction
temperature were prepared and evaluated by FT-IR, UV-vis and fluorescence detection to
estimate and summa rize the forming rules and fluorescence mechanism of CDs. Results
indicated the optima l reaction temperature was 200
o
C, the quantum yie ld were measured to
be 79.7%. The fluorescence of CDs was determined by carbon core and surface state and its
forming process mainly included the steps of cracking, po ly merization, carbonization and
growth of nuclei. The as-prepared CDs had excellent water solubility and biocompatibility,
which held a great potential in the fields of cell targeting and drug delivery.
1. Introduction
CDs are a new group of zero-dimension carbon nanomaterials or nanoparticles, the size of most CDs
are less than 10 nm [1-2].
In the broad sense, the chemical structure of CDs are consisted of two parts,
one is carbon core which is arised from sp
2
/sp
3
carbon, the other is surface state that derives from the
oxygen/nitrogen based groups or polymeric on the surface of CDs [3]. There are so many routes to
prepare CDs which is divided into top-down and bottom-up two methods [4], and the hydrothermal
method is commonly used due to the uniform heating, simple and safe process, high quantum yield
and excellent solubility of CDs.
In recent years, nitrogen-doped CDs (N-CDs) have drawn great attention due to the enhancement
of fluorescence [5], and one-step hydrothermal method using CA/EDA to synthesize N-CDs with
great photoluminescence and water solubility were common used in previous work [6]. However,
few reports were focused on preparing CDs with the best performance and summarizing the
formation rules and analysed fluorescence mechanism of CDs. Herein, in this paper, we took the
CA/EDA typical N-CDs as the research object and explored the effect of reaction temperature on the
fluorescence properties, discussed the formation rules, and finally evaluated the cytotoxicity of CDs.
Yang, K., Wang, C., Ding, S., Li, F. and Tian, F.
The Effect of Reaction Temperature on Fluorescence Properties of Carbon Dots.
In Proceedings of the International Workshop on Materials, Chemistry and Engineering (IWMCE 2018), pages 229-235
ISBN: 978-989-758-346-9
Copyright © 2018 by SCITEPRESS – Science and Technology Publications, Lda. All rights reserved
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