Novel carbon dots with dual excitation for imaging and silver ion detection in living cells

Abstract

Silver metal is employed in a broad range of applications in our daily lives and in industries. Pollution caused by silver ions (Ag+) has been significantly increasing, and hence, it is necessary to design a highly effective method for detection of Ag+ with high sensitivity and excellent selectivity. Herein, we report the use of novel nitrogen–fluorine--codoped carbon dots (NFCDs) with dual emission as probes for Ag+ detection. The fluorescence of NFCDs was quenched rapidly by Ag+ (<1 min) in aqueous solution. The NFCD probes showed not only a wide linear response range (0–10 and 10–45 μM) but also an extremely low detection limit (15 nM) for Ag+, indicating their high sensitivity. The fluorescence of NFCDs was quenched by Ag+ without any interference from other metal ions, exhibiting their excellent selectivity. In addition, the NFCDs were employed in cell staining and intracellular Ag+ detection in living cells. The results indicated that the NFCDs were accumulated in the cytomembrane, and their fluorescence was completely quenched by exogenous Ag+ in cells. This study provides the basis for the development of a novel and inexpensive probe to detect Ag+ for effective detection of pollutants and onset of clinical diseases.