Electrocatalytic Oxidation of Estrogenic Phenolic Compounds at a Nickel‐Modified Glassy Carbon Electrode

Abstract

This paper demonstrates for the first time, successful electrocatalytic oxidation of electroactive estrogenic phenolic compounds (EPCs) at a nickel-modified glassy carbon electrode (Ni-GCE). The electrode was evaluated in terms of electrocatalytic activity, sensitivity, linear dynamic range, limit of detection, and response stability. In comparison to bare glassy carbon electrode, current amplification was observed for EPCs at Ni-GCE, for example, for a 40 mM estrone at Ni-GCE was amplified by a factor of 1224. The Ni-GCE gave good figures of merit with no evidence of electrode fouling. As an example, the limit of detection (S/N = 3) for 17b-estradiol was 100 nM and the response precision (n = 5) was 3.4 %.

DPV and SWV Determination of Estrone Using a Cathodically Pretreated Boron‐Doped Diamond Electrode

“…The LOD values attained simply using the CPT BDD electrode (for both SWV and DPV) are equal or close, respectively, to that reported by Muna et al. 27 using a nickel‐modified GC electrode or that reported by Brocenschi et al. [54] by FIA using a CPT BDD electrode as detector.…”

“…However, as noted by Muna et al. 27, the electrochemical detection of these compounds can often be plagued by the strong irreversible adsorption of reaction products and intermediates, causing, in this case, a rapid decrease of the signal response, thus diminishing the life cycle of the electrode due to sensibility and reproducibility problems. Considering that films electrodeposited on the electrode surface are a serious hindrance to the electroanalysis of organic compounds, different approaches have been explored to minimize this effect.…”

“…More recently, Muna et al. 27 studied the electrocatalytic oxidation of four estrogens at a nickel‐modified GC electrode (Ni‐GC) using cyclic voltammetry. For estrone, they reported an LOD value of 0.10 µmol L −1 , which indicates that the modified GC surface promotes stability in the analytical determination of that compound.…”

An additional tool towards overcoming absence of specificity of carbon nanostructure-based electrochemical sensors—application to estriol and estradiol detection and distinction

“…Different physico-chemical principles have been successfully used for estriol and estradiol detection, like adsorptive cathodic stripping voltammetry [5], single-sweep polarography [6], surfactant-modified voltammetry using carbon paste electrodes [7], electrocatalytic oxidation at nickel-modified glassy carbon electrode [8], and voltammetry using borondoped diamond electrodes [9]. Graphene oxide (GO), reduced graphene oxide (rGO), and rGO modified with antimony nanoparticles (rGO-SbNPs) are attractive materials for the detection of estriol and estradiol because they show a pronounced electrochemical oxidation peak, showing high sensitivity and presenting constant sensitivity over a wide range of estriol and estradiol (see Fig.…”

Reduced graphene oxide-Sb2O5 hybrid nanomaterial for the design of a laccase-based amperometric biosensor for estriol

“…These results suggest that this novel graphene-based hybrid nanomaterial could be useful for the design of electrochemical biosensor devices for the determination of estriol in clinical and environmental samples. Reference rGO-SbNPs DPV 5.0x10 -10 2.0x10 -7 -1.4x10 -6 [34] MMIPs NPs/CPE CV 1.0 x10 -7 6.0x10 -7 -1.0x10 -4 [35] BDD SWV 1.7x10 -7 2.0x10 -7 -2.0x10 -5 [20] Ni-GCE CV 1.0 x10 -7 5.0x10 -6 -1.0x10 -4 [36] PPOMC SWV 5.0x10 -9 1.0x10 -8 -2.0x10 -6 [37] Pt/MWNTs/GCE SWV 6.2x10 -7 1.0x10 -6 -7.5x10 -5 [38] Lac/rGO/Sb2O5/GCE amperommetry 1.1x10 -8 2.5x10 -8 -1.03x10 -6 this work rGO-SbNPs: reduced graphene oxide-antimony nanoparticles; DPV: differential pulse voltammetry;…”