A Series of Cobalt-Based Coordination Polymer Crystalline Materials as Highly Sensitive Electrochemical Sensors for Detecting Trace Cr(VI), Fe(III) Ions, and Ascorbic Acid
Yue Wang, Jianxin Ma, Yue Zhang, Na Xu, Xiuli Wang
Abstract
Convenient, sensitive, and reliable detection of multiple heavy-metal ions is a significant and challenging task with the use of high-yielding and easily synthesized materials. To solve this challenge, five cobalt-based coordination polymers (CPs), [Co2(4-dptb)2(1,3-BDC)2]·2H2O (1), [Co(4-dptb)(5-DIP)] (2), [Co(4-dptb)(5-NIP)] (3), [Co(4-dptb)(5-AIP)] (4), and [Co(4-dptb)(5-MIP)] (5) (4-dptb = N3,N4-bis(pyridin-4-ylmethyl)thiophene-3,4-dicarboxamide, 1,3-BDC = 1,3-benzenedicarboxylate, 5-DIP = 5-hydroxyisophthalic acid, 5-NIP = 5-nitroisophthalic acid, 5-AIP = 5-methylisophthalic acid, 5-MIP = 5-aminoisophthalic acid), have been synthesized by hydrothermal methods. A remarkable electrochemical sensing for Cr(VI) and Fe(III) was confirmed by cyclic voltammetry (CV) and current–time curves (i–t). The results showed that all CPs have a low limit of detection (LOD) of Cr(VI) and Fe(III) and fast electrochemical responses of within 3 s. At the same time, compounds 1–5 have a significant electrocatalytic oxidation effect on ascorbic acid (AA) and can be used as electrochemical sensors for AA.