RESUMO
An electrochemical sensor has been developed based on ion imprinted polymer (IIP) and nanoporous gold (NPG) modified gold electrode (IIP/NPG/GE) for determination of arsenic ion (As3+) in different kinds of water. NPG with high conductivity, large specific surface area, and high biocompatibility was prepared by a green electrodeposition method. Then a layer of IIP was synthesized in situ on NPG surface by electropolymerization, in which As3+ was used as template ion and o-phenylenediamine as functional monomer. We used potassium ferricyanide and potassium ferrocyanide chelates as electrochemical probes to generate signals. The electrochemical behavior of IIP/NPG/GE (vs. Ag/AgCl) was studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The linear range for As3+ was 2.0 × 10-11 to 9.0 × 10-9 M, and the lower detection limit was 7.1 × 10-12 M (S/N = 3). This newly developed sensor has good stability and selectivity, and has been successfully applied to the As3+ determination of four kinds of water quality.
RESUMO
Aggregation-induced emission (AIE) materials have drawn great attention for applications as organic light-emitting diodes (OLED) and probes. The applications are, however, restricted by the complex syntheses and hydrophobic properties. Herein, a one-step synthesis of an AIE material based on imidazole hydrazone is assessed. Protonation of the imidazole-H leads to emission color change from yellow to green in the solid state. The emission color is recovered upon imidazole-H+ deprotonation. Moreover, the emission wavelength shifts from 532 to 572â nm by anion exchange. In addition, an enhanced emission (ΦF up to 22.6 %) was obtained with the Br- anion compared with NTf2 - , SbCl5 - , PF6 - , and OTf- anions. X-ray crystallography studies together with theoretical calculations show that the enhanced emission of hydrazone salts arises from strong hydrogen bonding between the hydrazone proton and the halide ion (Cl- or Br- ).