Premium
Electrofluorochromic Detection of Cyanide Anions Using a Nanoporous Polymer Electrode and the Detection Mechanism
Author(s) -
Ding Guoqiang,
Lin TingTing,
Zhou Rui,
Dong Yuliang,
Xu Jianwei,
Lu Xuehong
Publication year - 2014
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201403133
Subject(s) - nanoporous , cyanide , carbazole , chemistry , benzonitrile , electrochemistry , electrolyte , aqueous solution , polymer , photochemistry , quenching (fluorescence) , polymerization , electrode , inorganic chemistry , fluorescence , organic chemistry , quantum mechanics , physics
An electrofluorochromic (EFC) conjugated copolymer ( P EFC ) containing carbazole and benzothiadiazole (BTD) moieties is synthesized through Suzuki coupling followed by electrochemical polymerization, resulting in a nanoporous EFC polymer electrode. The electrode exhibits high sensitivity and selectivity in the EFC detection of cyanide anions (CN − ) in largely aqueous electrolyte (67 vol % water) because electrochemical oxidation of P EFC leads to significant fluorescence quenching, and the presence of different concentrations (1 to 100 μ M ) of CN − in the electrolyte can weaken the oxidative quenching to substantially different extents. Although P EFC is hydrophobic in the neutral state, it is converted to radical cation/dication states upon oxidation, rendering the P EFC some hydrophilicity. Moreover, its nanoporous morphology provides a large surface area and short diffusion distance, facilitating the movement of CN − in the electrolyte into the P EFC film to interact with receptors. Density functional theory calculations show that the noncovalent interaction between electron‐deficient BTD and nucleophilic CN − is energy favorable in the oxidized states in both aqueous and organic media, suggesting that the specific π − –π + interaction plays the main role in the CN − detection.