Simultaneous Square Wave Voltammetric Detection of Endocrine-Disrupting Agents Using a Nanocomposite of Magnetic Fe₃O₄Nanorods and Poly(3,4-Methylenedioxy)aniline

Abstract

In this report, the ultrasensitive simultaneous determination of bisphenol A (BPA), phenol, and 4-nitrophenol (4-NP) as hazardous phenolic endocrine-disrupting agents was explored by square wave voltammetry (SWV) using magnetic “needlelike” Fe3O4 nanorods (MNRs) and a poly­(3,4-methylenedioxy)­aniline (PMDAN) nanocomposite-modified graphite paste electrode (GPE). The MNRs had dimensions of 5.3 ± 1.1 nm in width and 61.4 ± 3.3 nm in length. A solid-state, green, and sustainable method incorporating mechanochemical reactions between 3,4-(methylenedioxy)­aniline as a novel aniline monomer and Fe­(III) chloride was used for the synthesis of MNR-PMDAN. The MNR-PMDAN nanocomposite-modified GPE (MNR-PMDAN/GPE) exhibited three well-defined anodic peaks at 0.82, 0.96, and 1.20 V vs Ag/AgCl for BPA, phenol, and 4-NP, respectively, in an acidic electrolyte solution at pH 2.0. The calibration curves were linear up to 40.0, 150.0, and 125.0 μM with a limit of detection of 4.3, 15.3, and 16.8 nM for BPA, phenol, and 4-NP, respectively. MNR-PMDAN/GPE was also used for the determination of BPA, phenol, and 4-NP in real samples with recoveries in the range of 95.2–104.9%. The results of this study demonstrate that the MNR-PMDAN nanocomposite is suitable for applications toward the development of a handheld device for on-field prescreening of hazardous endocrine-disrupting pollutants.

A designed miniature sensor for the trace level detection and degradation studies of the toxic dye Rhodamine B

“…5B . This slope which is very close to Nernstian slope (59 mV pH −1 ) 37 indicates that equal number of electrons and protons are involved in the oxidation of Rhodamine B. The inflection point of the plot represents pKa i.e.…”

Electrochemical Sensor for Detection and Degradation Studies of Ethyl Violet Dye

“…The anodic peak shifting linearly toward the lower potential with increased pH of the medium indicates the involvement of protons in the electrochemical process (Figure 8B). On the pH vs potential plot, the slope value 57 mV/pH (Figure 8B) is close to the Nernstian slope (59 mV/pH), 40 which indicates that equal numbers of electrons and protons were involved in the oxidation of ethyl violet. At the modified electrode, the f CNTs facilitate the electron transfer rate due to their conductive nature and support adsorption of EV during the preconcentration step of SWASV.…”

Ferrocene‐Functionalized Multiwalled Carbon Nanotubes for the Simultaneous Determination of Dopamine, Uric Acid, and Xanthine

“…Figure S3(A–D) shows typical CVs of a unmodified GPE, GPE/Fc, GPE/MWCNTs, and of GPE/Fc‐MWCNTs at various scan rates in potential range of −0.2 to 0.6 V versus Ag/AgCl in the presence of 1.0 mM of [Fe(CN) 6 ] 3− and 0.1 M KCl as supporting electrolyte. The Randles‐Sevçik equation was used for determination of effective surface area of our electrodes; [72] …”