Yavarinasab Adel, Abedini Mostafa, Tahmooressi Hamed, Janfaza Sajjad, Tasnim Nishat, Hoorfar Mina
School of Engineering, University of British Columbia, Kelowna, BC V1V 1V7, Canada.
Abidi Pharmaceuticals, Research and Development Centre, Tehran 1389776363, Iran.
Polymers (Basel). 2021 Dec 22;14(1):31. doi: 10.3390/polym14010031.
In this study, we analyzed the application of potentiodynamic electrochemical impedance spectroscopy (PDEIS) for a selective in situ recognition of biological trace elements, i.e., Cr (III), Cu (II), and Fe (III). The electrochemical sensor was developed using the electropolymerization of aniline (Ani) on the surface of the homemade pencil graphite electrodes (PGE) using cyclic voltammetry (CV). The film was overoxidized to diminish the background current. A wide range of potential (V = -0.2 V to 1.0 V) was investigated to study the impedimetric and capacitive behaviour of the PAni/modified PGE. The impedance behaviors of the films were recorded at optimum potentials through electrochemical impedance spectroscopy (EIS) and scrutinized by means of an appropriate equivalent circuit at different voltages and at their corresponding oxidative potentials. The values of the equivalent circuit were used to identify features (charge transfer-resistant and double layer capacitance) that can selectivity distinguish different trace elements with the concentration of 10 μM. The PDEIS spectra represented the highest electron transfer for Cu (II) and Cr (III) in a broad potential range between +0.1 and +0.4 V while the potential V = +0.2 V showed the lowest charge transfer resistance for Fe (III). The results of this paper showed the capability of PDEIS as a complementary tool for conventional CV and EIS measurement for metallic ion sensing.
在本研究中，我们分析了动电位电化学阻抗谱（PDEIS）在选择性原位识别生物微量元素（即Cr(III)、Cu(II)和Fe(III)）方面的应用。使用循环伏安法（CV）在自制铅笔石墨电极（PGE）表面通过苯胺（Ani）的电聚合制备了电化学传感器。对该膜进行过氧化处理以降低背景电流。研究了较宽的电位范围（V = -0.2 V至1.0 V），以研究聚苯胺/修饰PGE的阻抗和电容行为。通过电化学阻抗谱（EIS）在最佳电位下记录膜的阻抗行为，并在不同电压及其相应氧化电位下借助合适的等效电路进行仔细研究。等效电路的值用于识别能够选择性区分浓度为10 μM的不同微量元素的特征（电荷转移电阻和双层电容）。PDEIS谱表明，在+0.1至+0.4 V的宽电位范围内，Cu(II)和Cr(III)具有最高的电子转移，而电位V = +0.2 V时，Fe(III)的电荷转移电阻最低。本文结果表明，PDEIS作为传统CV和EIS测量用于金属离子传感的补充工具的能力。
