Self-doped Anthranilic Acid-Pyrrole Copolymer/Gold Electrodes for Selective Preconcentration and Determination of Cu(I) by Differential Pulse Anodic Stripping Voltammetry

Abstract

Electropolymerization of anthranilic acid/pyrrole (AA/PY) at solid substrate electrodes (platinum, gold, and glassy carbon) gave stable and water-insoluble films under a wide range of pH. Combining high conductivity of the polypyrrole (PPY) and pH independence of the electrochemical activity of the self-doped carboxylic acid-substituted polyaniline allows us to prepare an improved functionalized PPY-modified electrode to collect and measure Cu(I) species. The differential pulse stripping analysis of the copper ions using a polyanthranilic acid-co-polypyrrole (PAA/PPY)-modified electrode consisted of three steps: accumulation, electrochemical reduction to the elemental copper and stripping step. Factors affecting these steps, including electropolymerization conditions, accumulation and stripping medium, reduction potential, reduction time and accumulation time, were systematically investigated. A detection limit of 5.3 × 10 -9 M Cu(I) was achieved for a 7.0 min accumulation. For 12 determinations of Cu(I) at concentrations of 1.0 × 10 -8 M, an RSD of 3.5% was obtained. The log Ip was found to vary linearly with log[Cu I ] in the concentration range from 7.0 × 10 -9 to 1.0 × 10 -5 M.

Anthranilic Acid: A Versatile Monomer for the Design of Functional Conducting Polymer Composites

“…When applied to an electrode, the PAA-Co-Cy composite was found to electrocatalyze the reduction of azidothymidine (AZT)-a potent antiviral drug used in the treatment of HIV. Nateghi and Fallahian (2007) employed a copolymer of pyrrole and anthranilic acid for the detection of copper ions [66]. Again, the carboxylate substituent played a pivotal role in the capture and preconcentration of the metal ion, thereby enabling its detection through electrochemical stripping techniques.…”

Electrode Materials (Bulk Materials and Modification)

“…Typically, Cu(II), Pb(II), Cd(II), Ag(I) and Hg(II) are among the most common analytes. [517][518][519][520][521][522][523][524][525][526][527] The role of the polymer layer on the electrode can either provide protection from surface fouling or selectivity toward the target analyte. In 1987, Florence and coworkers demonstrated the use of Nafion films as a permselective layer that allowed the diffusion of metals to reach the electrode surface while organic substances and proteins were maintained away, avoiding surface fouling.…”

“….). [520][521][522][523][524][525][526][527] Heavy metals are generally detected by pulsed voltammetry techniques with detection limits in the nM range. Molecularly imprinted polymers have been developed for the detection of small organic molecules relevant to environmental applications.…”

Strategies, Development and Applications of Polymer-Modified Electrodes for Stripping Analysis

“…Electropolymerisation of anthranilic acid and pyrrole at platinum, gold, or glassy carbon electrodes gave stable polymer-coated electrodes that were then employed to prepare an improved functionalized PPY-modified gold electrode to collect and measure Cu(I) species by DPASV down to 5 nM levels [69].…”