Versatile Azido-Functionalized Carbon Dots for Cancer Cell Imaging

Herein, we adopt a bottom-up approach to achieve the first one-pot synthesis of azido-functionalized carbon dots (CDs) through a unique glucose–azidoamine two-component recipe. The azido content on CDs can be well-tuned by partially replacing the azidoamine with a methoxyamine diluent during the synthesis. Task-oriented payloads could then be conveniently connected to the azido-functionalized CDs through click chemistry. As a demonstration, we exploit strain-promoted alkyne–azide cycloaddition to obtain folate-decorated CDs, which can selectively display fluorescence in tumor cell lines with elevated levels of folate receptors. This facile production of azido-functionalized CDs should provide huge advantages for future applications.