碳点的功能化及其在食品安全领域的应用

Functionalization of carbon dots and their applications in food safety

作为新型的传感材料,碳点在过去10年中受到了广泛的关注。由于制备方法相对单一,未经功能化碳点的表面有效传感作用位点的种类受到了限制(多为羧基、羟基、醛基等含氧官能团),导致其选择性和灵敏度不佳。因此,功能化在开发碳点传感器中扮演了重要的角色。碳点的功能化主要分为两大类:掺杂改性及表面修饰。掺杂改性是在碳点的骨架结构中引入新的元素,一方面能够实现碳点的光学改性,另一方面也可以在其表面形成新的作用位点用于传感。表面修饰是在碳点表面原有结构的基础上,通过共价或非共价的形式与其他功能结构相结合,从而拓展碳点的选择性并提升其灵敏度。本文对近8年来碳点功能化及其在食品安全检测领域应用的相关研究进展进行了系统性的梳理,为开发基于功能化碳点的食品快检设备提供一些新的思路。

Almost two decades have passed since the discovery of carbon nanodots(CDs).As a promising family of optical nanomaterials,CDs have high emission efficiency,excellent water solubility,and good bio-compatibility;in addition,they are inexpensive and can be produced by a facile synthesis process.Because of these advantages,CDs have drawn tremendous attention for use in the development of novel optochemical sensors.However,the application scope of chemical sensors based on pristine CDs is restricted because the synthetic methods and starting materials for the CDs give rise to a great limitation of their surface chemical structures.Therefore,pristine CDs need to be functionalized so that they can be employed in sensing applications,with high sensing capability.Typically,functionalization can be classified into two types:doping and surface modification.Doping,as an effective method for introducing new elements to the skeleton of CDs,not only helps manipulate the energy bang-gap of pristine CDs,but also brings the specific acceptor of the target analyte to the CD matrix.Surface modification is a conventional functionalization method that allows one to manipulate the surface chemical structure of CDs in a covalent or non-covalent fashion,so that the selectivity and sensitivity of pristine CDs can be sequentially improved.In this paper,we review the research progress in the functionalization of CDs over the last eight years based on the publications from Web of Science,and systematically summarize the applications of CD-based sensors in the area of food safety.Although this review is incomprehensive due to space restrictions,it can shed fresh light on the development of CD-based rapid sensors for food safety applications in the near future.