8-hydroxyquinoline-functionalized SBA-15 modified carbon paste electrode as a voltammetric sensor for the determination of copper ions in tea

In this work, the presence of Cu(II) in green tea was determined by a novel carbon paste electrode containing functionalized SBA-15 using the anodic stripping voltammetry method. The functionalized SBA-15 was modified with 8-hydroxyquinoline. Due to the excellent electrochemical properties, Cu(II) over a wide range from 1 μg L-1 to 800 μg L-1 can be examined by the electrode modified with 8-hydroxyquinoline-functionalized SBA-15 and exhibits good linear response. The detection limit was 0.7 μg L-1. With good reproducibility and stability, the electrode could be applied to measure the level of Cu(II) in tea, and the results agreed well with those obtained by Inductively Coupled Plasma Optical Emission (ICP-OES). Furthermore, using a quantum chemistry computational method, the reasonable pathways of the electrodes with Cu(II) were determined. It is shown that the reaction of Cu(II)+8-HQNHCH2CH3CH3 is energetically favorable. Copyright © 2016 American Scientific Publishers All rights reserved.