Rapid detection of Ag+ in food using cholesteric chiral artificial receptor L5

A cholesteric chiral artificial receptor L5 was synthesized, which recognized and cooperated with Ag + in metal ions, and a rapid method for detecting Ag + was established in food. It was found by fluorescence spectroscopy analysis that the L5 could recognize Ag + in DMSO solution; with the help of fluorescence and UV titration, job test and interference test to verify its recognition pattern, and founded that the L5 and guest Ag + were combined with 1:1 coordination ratio. Then, the recognition mechanism between L5 and guest Ag + was explored by measures of nuclear magnetic titration, infrared spectroscopy, electron microscopy and computer molecular simulation. It was speculated that the carbonyl oxygen atom near the amide of the MeO-PhCONH group and the carbonyl oxygen atom of the –COOCH 3 group cooperated with Ag + throµgh electrostatic gravitational interaction. This method was used to establish the detection of Ag + in food in which the detection limit of L5 for Ag + was derived as 0.13 µmol/L, and the silver ions in wolfberry, milk powder,wheat flour, tea leaf and soybean were accurately detected. This method can be used to quantify Ag + content in actual samples accurately and efficiently.