Microwave-assisted synthesis of nitrogen-rich carbon dots as effective fluorescent probes for sensitive detection of Ag+

A simple strategy for the synthesis of fluorescent nitrogen-rich carbon dots (N-dots) is developed through microwave-assisted reaction of 2-azidoimidazole with different hydroxyl compounds. With the increase of hydroxyl groups of the crosslinkers, the emission property of the corresponding N-dots was enhanced. Among them, N-dots with 2-azidoimidazole and glycerol as the starting materials showed high monodispersity, good stability, excellent water solubility and strong fluorescence emission with fluorescence quantum yield up to 27.9%. These N-dots were further employed as an effective chemosensor for Ag+ analysis via the static quenching effect and a good linear range of Ag+ detection was obtained from 20 nM to 6 mu M with a limit of detection of 6.3 nM, displaying high selectivity toward Ag+ detection in real samples.