Photoluminescent Green Carbon Nanodots from Food-Waste-Derived Sources: Large-Scale Synthesis, Properties, and Biomedical Applications

• Published in: ACS applied materials & interfaces 2014-03, Vol.6 (5), p.3365-3370
• Main Authors: Park, So Young, Lee, Hyun Uk, Park, Eun Sik, Lee, Soon Chang, Lee, Jae-Won, Jeong, Soon Woo, Kim, Chi Hyun, Lee, Young-Chul, Huh, Yun Suk, Lee, Jouhahn
• Format: Article
• Language: English
• Subjects: Animals; Carbon - chemistry; Cell Line; Cell Survival - drug effects; Cells - chemistry; Cells - cytology; Cercopithecus aethiops; Cricetinae; Cricetulus; Fruit - chemistry; Green Chemistry Technology; Luminescence; Mice; Nanoparticles - chemistry; Nanoparticles - toxicity; Vegetables - chemistry; Waste Products - analysis
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/am500159p

We have developed a simple approach for the large-scale synthesis of water-soluble green carbon nanodots (G-dots) from many kinds of large food waste-derived sources. About 120 g of G-dots per 100 kg of food waste can be synthesized using our simple and environmentally friendly synthesis approach. The G-dots exhibit a high degree of solubility in water because of the abundant oxygen-containing functional groups around their surface. The narrow band of photoluminescence emission (400–470 nm) confirms that the size of the G-dots (∼4 nm) is small because of a similar quantum effects and emission traps on the surfaces. The G-dots have excellent photostability; their photoluminescence intensity decreases slowly (∼8%) under continuous excitation with a Xe lamp for 10 days. We carried out cell viability assay to assess the effect of cytotoxicity by introducing G-dots in cells such as Chinese hamster ovary cells (CHO-K1), mouse muscle cells (C2C12), and African green monkey kidney cells (COS-7), up to a concentration of 2 mg mL–1 for 24 h. Due to their high photostability and low cytotoxicity, these G-dots are excellent probes for in vitro bioimaging. Moreover, the byproducts (not including G-dots) of G-dot synthesis from large food-waste derived sources promoted the growth and development of seedlings germinated on 3DW-supplemented gauze. Because of the combined advantages of green synthesis, high aqueous stability, high photostability, and low cytotoxicity, the G-dots show considerable promise in various areas, including biomedical imaging, solution state optoelectronics, and plant seed germination and/or growth.