AuNPs-functionalized PANABA-MWCNTs nanocomposite-based impedimetric immunosensor for 2,4-dichlorophenoxy acetic acid detection

Giovanni Fusco; Francesca Gallo; Cristina Tortolini; Paolo Bollella; Federica Ietto; Antonella De Mico; Andrea D'Annibale; Riccarda Antiochia; Gabriele Favero; Franco Mazzei

doi:10.1016/j.bios.2016.10.016

AuNPs-functionalized PANABA-MWCNTs nanocomposite-based impedimetric immunosensor for 2,4-dichlorophenoxy acetic acid detection

Biosens Bioelectron. 2017 Jul 15:93:52-56. doi: 10.1016/j.bios.2016.10.016. Epub 2016 Oct 5.

Affiliations

¹ Department of Chemistry and Drug Technologies, Sapienza University of Rome, Italy; Department of Chemistry, Sapienza University of Rome, Italy.
² Department of Chemistry and Drug Technologies, Sapienza University of Rome, Italy.
³ Department of Technological Innovations and Safety of Plants, Products and Anthropic Settlements, National Institute for Insurance Against Accidents at Work, Rome, Italy.
⁴ Department of Chemistry, Sapienza University of Rome, Italy; Institute of Molecular Biology and Pathology - National Research Council, Italy.
⁵ Department of Chemistry, Sapienza University of Rome, Italy.
⁶ Department of Chemistry and Drug Technologies, Sapienza University of Rome, Italy. Electronic address: gabriele.favero@uniroma1.it.

PMID: 27743865
DOI: 10.1016/j.bios.2016.10.016

Abstract

In this work, we developed an impedimetric label-free immunosensor for the detection of 2,4-Dichlorophenoxy Acetic Acid (2,4-D) herbicide either in standard solution and spiked real samples. For this purpose, we prepared by electropolymerization a conductive polymer poly-(aniline-co-3-aminobenzoic acid) (PANABA) then we immobilized anti-2,4-D antibody onto a nanocomposite AuNPs-PANABA-MWCNTs employing the carboxylic moieties as anchor sites. The nanocomposite was synthesized by electrochemical polymerization of aniline and 3-aminobenzoic acid, in the presence of a dispersion of gold nanoparticles, onto a multi-walled carbon nanotubes-based screen printed electrode. Aniline-based copolymer, modified with the nanomaterials, allowed to enhance the electrode conductivity thus obtaining a more sensitive antigen detection. The impedimetric measurements were carried out by electrochemical impedance spectroscopy (EIS) in faradic condition by using Fe(CN)₆^3-/4- as redox probe. The developed impedimetric immunosensor displayed a wide linearity range towards 2,4-D (1-100ppb), good repeatability (RSD 6%), stability and a LOD (0.3ppb) lower than herbicide emission limits.

Keywords: 2,4-Dichlorophenoxy acetic acid; Au nanoparticles; Impedimetric immunosensor; Nanocomposite; Polyaniline; Screen printed electrodes.

MeSH terms

2,4-Dichlorophenoxyacetic Acid / chemistry
2,4-Dichlorophenoxyacetic Acid / isolation & purification*
Aniline Compounds / chemistry
Biosensing Techniques*
Dielectric Spectroscopy
Electrochemical Techniques*
Electrodes
Gold / chemistry
Limit of Detection
Metal Nanoparticles / chemistry
Nanotubes, Carbon / chemistry
Polymers / chemistry

Substances

Aniline Compounds
Nanotubes, Carbon
Polymers
2,4-Dichlorophenoxyacetic Acid
Gold
aniline