意式咖啡中碳量子点的性质及其毒性研究

Characterization and Toxicity of Carbon Quantum Dots from Espresso

碳量子点(Carbon quantum dots,CQDs)是一种碳基纳米材料,热加工食品中含有CQDs,且有一定的毒性。文章用2种不同的烘焙时间(10 min和20 min)从230℃烘焙的意式咖啡中提取并纯化CQDs,对其形态大小、元素组成、官能团和荧光性质进行测定,并分析了CQDs的毒性。结果表明CQDs呈球形,且大小均匀,烘焙时间10 min和20 min CQDs的平均直径分别为(4.01±1.28)nm和(1.44±0.36)nm;X射线光电子能谱和傅里叶红外光谱的结果显示CQDs具有羟基、甲基、羰基等官能团;细胞毒性实验的结果表明咖啡豆烘焙时间越长,CQDs尺寸越小,毒性越大,当CQDs的浓度达到1.0 mg/mL时,细胞凋亡率从对照组的6.80%分别增加到10 min处理组的12.90%和20 min处理组的24.95%。该研究阐明了咖啡豆中CQDs的理化性质和细胞毒性,为咖啡的安全生产提供基础,为食源性纳米材料的深入认识提供参考。

Carbon quantum dots(CQDs)are a kind of carbon-based nanomaterial.Many hot processed foods contain CQDs,and CQDs have certain toxicity.In this paper,CQDs was extracted and purified from Italian coffee roasted at 230℃with two different roasting times(10 min and 20 min).The morphological size,elemental composition,functional groups and fluorescence properties of CQDs were determined,and the toxicity of CQDs was studied.Our results showed that CQDs is spherical and uniform in size,and the diameter of 10 min and 20 min CQDs is about(4.01±1.28)nm and(1.44±0.36)nm,respectively.X-ray photoelectron spectroscopy and Fourier infrared spectrum analysis showed that CQDs had hydroxyl,methyl,carbonyl and other functional groups.The results of cytotoxicity experiment showed that CQDs had certain toxicity,and the longer the coffee beans were roasted,the smaller the size of CQDs and the greater the toxicity.When the concentration of CQDs reached 1.0 mg/mL,the apoptosis rate increased from 6.80%in the control group to 12.90%in the 10 min treatment group and 24.95%in the 20 min treatment group.This study elucidated the physical properties,chemical properties and cytotoxicity of CQDs in coffee beans,which provides a basis for the safe production of coffee and a reference for further understanding of foodborne nanomaterials.