Sensitive and Selective Fluorescent and Colorimetric Sensor for Ag+ Based on the Supramolecular Self‐Assembly in Semi‐Water

Abstract

Specific recognition of ultratrace levels of ions in semi‐water using super‐quicker methods is still a challenge for environmental monitoring. Herein we report a fluorescent and colormetric sensor (ZH) based on supramolecular self‐assembly, whose structure was destroyed by the addition of ultratrace of silver ions. The process promoted either naked eye visible color changes or fluorescence intensity quenched in conjunction with a wide pH range. Systematic studies revealed very high selectivity (0.07 µmol/L) for silver ions, and other common cations, e.g., Hg2+, Cu2+, Cd2+, Pb2+ had nearly no influence on the sensing behavior. This sensor also served as a multiple use of component in sensing materials by addition of I− into the mixture of ZH and Ag+ (about 5 times). What's more, ZH containing filter paper emerged distinct color and fluorescence changes upon exposure to silver (Ag+), which could be used as a portable method to undertake field testing for Ag+.