A Novel Highly Selective "Turn‐On" Fluorescence Sensor for Silver Ions Based on Schiff Base

Abstract

A novel optical chemical sensor L was designed and synthesized for the determination of silver ions. The sensor L was derived from 1‐naphthaldehyde and 3,4,5‐tris(hexadecyloxy)benzohydrazide. The sensor L shows high sensitivity and selectivity for Ag+ detection in comparison to other metal cations (Mg2+, Ca2+, Al3+, Cr3+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, Pb2+) and has no significant response to other common metal cations. Upon addition of Ag+, the fluorescent emission of the sensor L was enhanced dramatically but other metal cations had no same response. The detection limit for Ag+ was 1.2×10−7 mol/L. Therefore, the sensor L is useful for Ag+ detection with some advantages including sensitivity, selectivity, simplicity and low‐cost.

A novel thiosemicarbazone Schiff base derivative with aggregation-induced emission enhancement characteristics and its application in Hg2+ detection

“…Hg 2+ addition, the signals for N-H show a downfield shift and appear at 12.83, 10.08, 9.53 ppm. Concomitantly, the signals for the protons on the thiosemicarbazide moiety are downfield shifted,whereas the signals for the protons on the benzoquinoxaline moiety were lowfield shifted due to the charge density of the thiosemicarbazones-Hg 2+ moiety was increased, promoted the intramolecular charge mobility of M1[52][53]. These observations indicated that the thiosemicarbazide segment in M1 is involved in the chemosensor's coordination with Hg 2+ and formed a 2:1 complex between Hg 2+ and M1[54][55][56].…”