Green synthesis of orange emissive carbon dots for the detection of Agand their application via solid-phase sensing and security ink.

Fluorescent carbon dots (CDs) have attracted considerable interest due to their superior optical properties and facile preparation. In this work, O-phenylenediamine and melamine were used as precursors for the one-step hydrothermal synthesis of novel orange emissive CDs (O-CDs) in an aqueous solution. The fluorescence intensity (580 nm) of the O-CDs exhibited a good linear relationship with Agin the range of 0.0-50.0M with the detection limit of 0.289M. Moreover, the O-CDs were successfully used to determine Agin biological samples (Hela cells) because of their low cytotoxicity, and good biocompatibility. Besides, the O-CDs-doped solid-phase detection materials (test paper and hydrogel) were employed to monitor Agqualitatively and quantitatively, indicated that the O-CDs had a great capacity for the detection of Agin biological and environmental areas. Based on their extraordinary fluorescence property, the O-CDs could also be used as security ink. Overall, based on their excellent fluorescent performance, the CDs in this study have significant potential for practical application toward solid-phase sensing and security ink.