Based on FRET to construct color-tunable ultralong lifetime room temperature phosphorescent carbon dots in aqueous solution.

Room temperature phosphorescent (RTP) Carbon Dots have been capturing increasing attention in recent years, while building a general method to adjust the emission color of RTP carbon dots is still a big challenge. Herein we report a simple method that combine the carbon nanodots and dyes (R6G and DCF) in SiO nanosphere to get a series of multicolor RTP nanodots (CD@SiO@dye) with long lifetime in aqueous solution. Leverage on chitosan quaternary ammonium as matrix and diethylenetriamine as N-doping resource to form a cross-linked skeleton as a luminescent center (namely CD), and a rigid network is formed by silica encapsulation (CD@SiO) to restrict the non-radiative transition process to generate the phosphorescence.