摘要
为改善石墨烯量子点的光学性质,设计并合成了五乙烯六胺和十二胺功能化石墨烯量子点(PEHAGQD-DA)。将柠檬酸和五乙烯六胺混合,170℃热解0.5 h后加入十二胺,继续反应1.5 h得到PEHA-GQDDA。PEHA-GQD-DA由尺寸仅为1~3 nm的石墨烯片组成,片边缘含有丰富的功能基团。五乙烯六胺的引入显著提高了量子点的荧光发射,荧光量子产率达到72.7%,明显高于单独柠檬酸热解所制备的石墨烯量子点。引入十二胺,使PEHA-GQD-DA容易通过细胞膜磷脂双分子层进入到细胞内部。PEHA-GQD-DA对环境pH值表现出极佳的光学响应行为。在pH 1.0~6.5时,荧光强度随pH值增加而线性增强。随pH值的变化,荧光光谱也发生改变,最大发射波长与pH值之间存在良好的线性关系。在pH 6.5~12.0时,荧光光谱不再随pH值变化而变化,但荧光强度随pH值增大而线性减少。常见无机离子和小分子化合物不影响PEHA-GQDDA对pH值的荧光响应。PEHA-GQD-DA已成功应用于环境水样pH值的荧光检测和Hela细胞成像。
Functional groups may change the electrical characteristics of graphene quantum dots,thus leading to the improvement of their properties and related applications.To improve the optical properties,we designed and synthesized pentaethylene hexamine and dodecylamine functionalized graphene quantum dots(PEHA-GQD-DA).Citric acid was mixed with pentaethylene hexamine and heated at 170℃for 0.5 h.Then dodecylamine was added and the reaction was continued at 160℃for 1.5 h to obtain PEHA-GQD-DA.The Yesults revealed that the PEHA-GQD-DA was composed of the graphene sheets from 1 nm to 3 nm,and their edges contained abundant functional groups.The introduction of pentaethylene hexamine greatly improved the fluorescence emission.The fluorescence quantum yield reached 72.7%,which was much higher than that of the GQD prepared by the thermal hydrolysis of single citric acid.The introduction of dodecylamine created a special amphiphilic structure that allows the quantum dots more likely to enter cell through the phospholipid bilayer of cell membrane.The PEHA-GQD-DA exhibited an excellent optical behavior for pH value of the medium.Within pH range of 1.0-6.5,the fluorescence intensity increased with the increase of pH value.The fluorescence spectrum sensitively changed with the change of pH value.There was a good linear relationship between the maximum emission wavelength and the pH value.When the pH was in the range of 6.5-12.0,the fluorescence spectrum didn't change with the change of pH value.However,its fluorescence intensity linearly decreased with the increase of pH value.The existence of common inorganic ions and organic small molecules does not interfere with pH response of the quantum dots.The PEHA-GQD-DA has been successfully applied to fluorescent detection of pH value in water samples and Hela cell imaging.
作者
严平
李在均
YAN Ping;LI Zai-Jun(School of Chemical and Materials Engineering,Jiangnan University,Wuxi 214122,China)
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2018年第5期670-677,共8页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金项目(No.21576115)资助~~
