Selective determination of Ag using Salecan derived nitrogen doped carbon dots as a fluorescent probe.

We report that nitrogen doped carbon dots (N-CDs) represent a viable fluorescent probe for the determination of Ag. The N-CDs can be fairly easily prepared by a hydrothermal treatment method using Salecan and dicyandiamide as the precursors, display excitation/emission maxima of 350/438nm. The N-CDs have an average diameter of about 3.8nm. The N-CDs exhibited blue fluorescence (quantum yield of 13.2%) and could response to Ag selectively and sensitively. Other ions nearly had no interference. The probe has excellent selectivity, high sensitivity, and a linear response range that extends from 0 to 40μM. The limit of detection is as low as 1.12×10mol/L. The method was applied to the determination of Ag dissolved in water.