Systematic safety evaluation on photoluminescent carbon dots

Kan Wang,Yan Wo,Guangxia Shen,Guo Gao,Zhongcai Gao,Yuxia Wang,Daxiang Cui

doi:10.1186/1556-276x-8-122

Abstract

Photoluminescent carbon dots (C-dots) were prepared using the improved nitric acid oxidation method. The C-dots were characterized by tapping-mode atomic force microscopy, and UV–vis absorption spectroscopy. The C-dots were subjected to systematic safety evaluation via acute toxicity, subacute toxicity, and genotoxicity experiments (including mouse bone marrow micronuclear test and Salmonella typhimurium mutagenicity test). The results showed that the C-dots were successfully prepared with good stability, high dispersibility, and water solubility. At all studied C-dot dosages, no significant toxic effect, i.e., no abnormality or lesion, was observed in the organs of the animals. Therefore, the C-dots are non-toxic to mice under any dose and have potential use in fluorescence imaging in vivo, tumor cell tracking, and others.

Highlights

Materials and methods Preparation and characterization of carbon nanodots carbon dots (C-dots) were prepared using the improved nitric acid oxidation method
C-dots are found to have the advantages of chemical inertness, low cytotoxicity, and good biocompatibility
Each group had 10 female and 10 male mice that were intravenously exposed to C-dots through a single tail injection of either 5.1 or 51 mg/kg body weight (BW)

Summary

Background

The importance of fluorescent nanoprobes in biomedical research and practice is rapidly increasing with the rapid developments in fluorescence microscopy, laser technologies, and nanotechnology. Fluorescent carbon dots (C-dots), a novel form of nanocarbon, have the inherent properties of traditional semiconductor-based quantum dots (e.g., size- and wavelength-dependent luminescence emissions, resistance to photobleaching, and ease of bioconjugation). Apart from these properties, C-dots possess special features such as physicochemical stability, photochemical stability, and non-blinking behavior [1,2,3]. The preparation methods of C-dots are relatively simple, low cost, and applicable in large scales. Carbon is not considered as an intrinsically toxic element, the specific material configurations and structures of C-dots may be potential risks to human health, thereby raising public concern [22]. C-dots are found to have the advantages of chemical inertness, low cytotoxicity, and good biocompatibility

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