关于碳点性能提升的研究进展

Recent Progress in the Performance Improvements of Carbon Nanodots

与传统半导体量子点相比,碳点(CDs)由于具有较强的抗光漂白性,可调的发光性能,低毒性和良好的生物相容性而引起研究者的极大兴趣。合成CDs的方法主要包括自上而下法和自下而上法。传统合成方法所制备的裸CDs由于量子产率较低,CDs形成机制不明确,应用也受到一定限制。合成过程中或合成后的修饰可有效提高CDs的量子产率和荧光性能,从而拓宽其在生物成像、探针、光催化剂、生物药物载体、光电材料等领域的应用。本文将对近年来有关CDs的几种修饰方法:形成金属纳米粒子-CDs复合物、杂原子掺杂和表面功能化的理论研究及应用加以综述,并对当前需要解决的问题以及今后的研究发展方向进行了探讨。

In contrast with traditional semiconductor quantum dots,the novel carbon nanodots（CDs）have attracted great interests in recent years owing to their high resistance to photo bleaching,tunable luminescence properties,low toxicity and good biocompatibility for numerous exciting applications.CDs are quasi-spherical carbon nanoparticles with a diameter of less than 10 nm,which are made up of sp2 carbon or amorphouscarbon aggregations and possess many functional groups such as epoxy,ether,carbonyl,hydroxyl,and carboxylic acid on their surface.Up to now,extensive efforts have been devoted to the synthesis of CDs,including ＂top-down＂ and ＂ bottom-up＂ methods.Bare CDs obtained from the traditional synthesis method suffer a drawback of low quantum yield,so their applications are limited.The formation of the CDs and the metal nanoparticle complexes improves the CDs properties by the corresponding metal nanoparticles,like gold nanoparticles（AuNPs）and silver nanoparticles（AgNPs）,and broadens the scope of their applications.Doping of heteroatoms is an efficient method to adjust the band gap and introduce new defect sites,which can enhance the quantum yield and improve the fluorescent properties of CDs.Surface engineering,including functionalization molecules attached on carbon nanodots,passivation and controlling oxidation can be used to fine-tune or obtain new fluorescence and other physicochemical properties,so that the application fields of CDs are broadened.In this review,we mainly focus on the theoretical and application studies of this three modified methods,and future development trends are provided.