Surface Modification Functionalized Carbon Dots

Carbon dots (CDs) smaller than 10 nm constitute a new type of fluorescent carbon‐based nanomaterial. They have attracted much attention owing to their unique structures and excellent photoelectric properties. Primitive CDs usually comprise carbon and oxygen and are synthesized in one step from various natural products or synthetic organic compounds, usually via microwave or hydrothermal methods. However, the uniformity of surface functional groups often make CDs lack the diversity of active sites required for specific applications. Therefore, the functionalization of CDs by specific groups is a powerful strategy for improving their photophysical and photochemical properties. This paper reviews surface modification strategies to overcome these shortcomings. Functionalizing CDs using covalent or non‐covalent modification can give them unique properties and broaden their applicability. Carbon dot materials are widely used in optoelectronic parts, biomedicine and detection fields because of their excellent optical properties. However, the performance of unmodified CDs materials in various fields of application is unsatisfactory. Therefore, there is an urgent need to review the construction methods of surface modification strategies for functional CDs materials in order to promote the continuous development of this field.