A New Voltammetric Sensor Based on a Glassy Carbon Electrode Modified with 8‐Hydroxyquinoline‐5‐sulfonic Acid

Abstract

The preparation and characterization of a new modified glassy carbon electrode (GCE) obtained by cycling the potential in a 8-hydroxyquinoline-5-sulfonic acid (HQSA) solution is presented. The influence of the deposition parameters on analytical performance is evaluated along with the comparison with the behavior of an activated GCE obtained by the same electrochemical treatment but in absence of HQSA. The modification by HQSA leads to improved electrochemical performances with respect to those of a bare or activated GCE. This is shown by applying the proposed electrode to the determination of some species of pharmaceutical and alimentary interest.

X-Ray Photoelectron Spectroscopic Characterization of Chemically Modified Electrodes Used as Chemical Sensors and Biosensors: A Review

“…Brunetti and Desimoni performed a CV/XPS investigation about the electropolymerization of 8-hydroxyquinoline-5-sulfonic acid (HQSA) at glassy carbon electrodes in hydrochloric acid solutions [82]. For a better understanding of the complex surface functionalization of the modified electrode, another GCE (ox-GCE) was also prepared by using the same electropolymerization parameters but in absence of HQSA.…”

“…The work completed a previous electrochemical investigation on the same CME [82]. Spectroscopic experiments involved acquiring survey and detailed scans of C 1s, O 1s, Si 2p, Cl 2p, N 1s, and S 2p regions of an HQSA powder standard sample as well as of GC electrodes cycled both in the presence and in the absence of HQSA.…”

XPS analysis of glassy carbon electrodes chemically modified with 8‐hydroxyquinoline‐5‐sulphonic acid

“…The HQSA modified electrode was evaluated as a sensor of some species of alimentary and pharmaceutical interest (dopamine, methylxanthines, food colorants, ascorbic acid). It can be shown that the above mentioned modification leads to improved electrochemical performances with respect to those of the bare GC electrode and of a GC electrode cycled under the same experimental conditions but in the absence of HQSA . This because of the adsorption capabilities made possible through electrostatic attraction and/or ion exchange between the negatively charged sulfonic acid functionality of HQSA and the positively charged groups of the analytes.…”

“…A study is in progress aimed to develop and characterize new modified glassy carbon (GC) electrodes suitable for quantifying species of environmental, alimentary, and pharmacological concern . In particular, a modified GC electrode was recently prepared by cycling the potential in 8‐hydroxyquinoline‐5‐sulphonic acid (HQSA) solutions . The electrochemical characterization concerned with the optimization of the deposition parameters (HQSA concentration, negative and positive potential limits, number of cycles, nature and pH of the supporting electrolyte).…”

“…It is well known, from investigations performed in different support electrolytes, that cycling GC electrodes in wide potential ranges such as the one used in our work (Refs. and the Experimental section), can also induce complex redox reactions on the GC electrode surface itself, even in the absence of HQSA. These reactions produce electrochemically active surface functional groups such as quinones, quinone‐like, phenolic and/or alcoholic groups …”