A Novel Ratiometric Fluorescent Probe for Ag+ Based on Arginine-Naphthalene Imide

A ratio fluorescent probe to detect Ag + using arginine-naphthalene imide (AN) had been elaborately designed and synthesized. The structure of AN was characterized by 1 HNMR and FTIR. The optical properties of AN were investigated by ultraviolet and fluorescence spectroscopy. The results indicated that the fluorescent intensity of AN was enhanced gradually with the increase of Ag + concentration, which was hardly affected by other metal ions such as Bi 3+ , Cd 2+ , Co 2+ , Cr 3+ , Cu 2+ , Fe 3+ , Hg 2+ , Pb 2+ , K + and Na + . A good linear correlation was displayed between the concentration of Ag + (ranging from 4.30 to 11.40 μmol L −1 ) and the fluorescence intensity ( R 2  = 0.9985). The detection limit was 0.1883 μmol L −1 . The mechanism of the sensor may be based on the principle of intramolecular charge transfer. It was expected that this novel ratio sensor could be used for the detection of silver ions in water.