Fabrication of dendritic nanoporous gold via a two-step amperometric approach: Application for electrochemical detection of methyl parathion in river water samples

Gilberto J Silva Junior; Jéssica Soares Guimarães Selva; Anandhakumar Sukeri; Josué M Gonçalves; Matias Regiart; Mauro Bertotti

doi:10.1016/j.talanta.2021.122130

Fabrication of dendritic nanoporous gold via a two-step amperometric approach: Application for electrochemical detection of methyl parathion in river water samples

Talanta. 2021 May 1:226:122130. doi: 10.1016/j.talanta.2021.122130. Epub 2021 Jan 23.

Authors

Gilberto J Silva Junior¹, Jéssica Soares Guimarães Selva¹, Anandhakumar Sukeri², Josué M Gonçalves¹, Matias Regiart³, Mauro Bertotti⁴

Affiliations

¹ Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Professor Lineu Prestes, 748, 05513-970, São Paulo, SP, Brazil.
² São Carlos Institute of Physics, University of São Paulo, Av. Trabalhador São-Carlense, 400 - Parque Arnold Schimidt, PO Box 369, CEP-13566-590, São Carlos, São Paulo, Brazil.
³ Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Professor Lineu Prestes, 748, 05513-970, São Paulo, SP, Brazil. Electronic address: matiasregiart@usp.br.
⁴ Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Professor Lineu Prestes, 748, 05513-970, São Paulo, SP, Brazil. Electronic address: mbertott@iq.usp.br.

PMID: 33676684
DOI: 10.1016/j.talanta.2021.122130

Abstract

In this work, nanoporous gold (NPG) was prepared according to three different approaches, such as (i) anodization-electrochemical reduction (A-ECR, NPG_A), (ii) dynamic hydrogen bubble template (DHBT, NPG_B), and (iii) the combination of both methods (NPG_A+B). Field-emission scanning electron microscopy (FE-SEM) and cyclic voltammetry (CV) were used to investigate the structural morphology and the electrochemical behavior of the fabricated materials. The NPG_A+B electrode showed a large amount of surface defects and/or edges, greater electrochemical surface area (2.5 cm²), and increased roughness factor (35.4). Such outstanding features of the NPG_A+B platform were demonstrated by the sensitive detection of methyl parathion (MP) in river water samples. CV results indicated nearly 25-fold, 6-fold, and 2.5-fold higher sensitivity for NPG_A+B compared to that of bare Au, NPG_A, and NPG_B, respectively. Differential pulse voltammetry (DPV) results show a linear behavior in the MP concentration range of 5-50 ng mL^-1 with a limit of detection (LOD) of 0.6 ng mL^-1 and limit of quantification (LOQ) of 2.0 ng mL^-1. Besides, the NPG_A+B sensor also revealed excellent selectivity towards MP detection in the presence of other interfering molecules or ions, reproducibility, and repeatability.

Keywords: Electrochemical sensor; Methyl parathion; Nanoporous gold; Non-enzymatic sensor; River water samples.