Use of a Schiff base-modified conducting polymer electrode for electrochemical assay of Cd(II) and Pb(II) ions by square wave voltammetry

Abstract

The work herein describes the electrochemical detection of heavy metal ions, specifically cadmium and lead. The introduction and modification of functional groups such as Schiff bases leads to an enhanced sensitivity of the electrode to analytes. In this study, a platinum electrode has, for the first time, been modified with poly(3,4ethylenedioxythiophene) (PEDOT/Schiff base) in CH 2 Cl 2 containing Bu 4 NPF 6 to detect cadmium (II) and lead (II) ions. The structures and morphologies of the polymer coatings were characterised via Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM), respectively. The electrochemical synthesis and redox state response in monomer-free synthesised films have been studied via cyclic voltammetry. Moreover, the effect of scan rate on the electrochemical behaviour of the modified electrodes was also studied. The voltammetric findings have been used to calculate the surface coverage required for the polymer films and the stability of polymer electrodes in the monomer-free solutions. Square wave voltammetry (SWV) was applied for the determination of cadmium (II) and lead (II) ion concentrations and to assess the effects of pH on aqueous samples. The limits of detection for the modified electrode for cadmium (II) and lead (II) were found to be 0.95 μg L -1 and 1.84 μg L -1 , respectively. These findings revealed that modified films can be considered good candidates for application in electrochemical detection devices.

On the Electroanalytical Detection of Zn Ions by a Novel Schiff Base Ligand-SPCE Sensor

“…In recent decades, electrochemical sensors have received great attention due to their good versatility in heavy metal ion detection. Several Schiff bases have been used in the development of innovative electrodes for the electrochemical recognition of heavy metal ions in water [ 5 , 6 , 7 ].…”

Voltammetric Determination of Hg2+, Zn2+, and Pb2+Ions Using a PEDOT/NTA-Modified Electrode

“…Environmental contamination from metals such as zinc, cadmium, lead, copper, cobalt, nickel, and mercury is a serious concern even at trace concentrations, − requiring the development of sensitive, selective, and accurate analytical methods to monitor such species . To date, many diverse techniques have been used for their detection, such as absorption, emission, fluorescence spectrometry, optical techniques, atomic absorption, and electrochemical technologies. − Electroanalytical methods are considered an efficient means of detecting a broad range of organic, inorganic, and heavy-metal ions because of their high accuracy, adaptability, sensitivity, rapid responses, and the fact that they are relatively inexpensive. − …”

Electrochemical aptasensor for Salmonella detection using Nafion-doped reduced graphene oxide

“…In comparison, the reduced graphene oxide (rGO) can partially overcome the aforementioned limitation because rGO is decorated with various functional groups, such as epoxy, carbonyl, carboxyl and hydroxyl groups which can be employed as an anchoring point for immobilization of molecules 7 . Conducting polymer poses high electron affinity, electronic conductivity, good mechanical strength and surface modifications of polymers further enhances the electrochemical performance 8,9 . Nafion (Nf) is the most widely used cation exchange conducting polymer for electrochemical applications due to its remarkable proton it into a functionalized nanocomposite provides good mechanical strength and enhanced conductivity comparable to pure graphene with improved biocompatibility.…”

“…7 Conducting polymers pose high electron affinity, electronic conductivity, and good mechanical strength, and surface modifications of polymers further enhance the electrochemical performance. 8,9 Nafion (Nf) is the most widely used cation exchange conducting polymer for electrochemical applications due to its remarkable proton conductivity and stability. 10 Thus, coupling graphene oxide with the Nafion polymer and reducing it into a functionalized nanocomposite provides good mechanical strength and enhanced conductivity comparable to pure graphene with improved biocompatibility.…”