McKeever, Colm, Callan, Sarah, Warren, Susan and Dempsey, Eithne (2022) Magnetic nanoparticle modified electrodes for voltammetric determination of propellant stabiliser diphenylamine. Talanta, 238 (123039). pp. 1-13. ISSN 0039-9140
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Abstract
The overall aim of the work was to advance electrochemical devices capable of analysis of forensically relevant
residues using rapid electrochemical sensor technology. In order to achieve this, electrochemical detection of the
propellant stabiliser diphenylamine (DPA) was achieved via voltammetry with signal enhancement realised in
the presence of iron oxide nanoparticle modified transducers. This allowed both mechanistic and analytical
evaluation with the aim to achieve the required selectivity and sensitivity for reliable detection. DPA electro-chemistry was examined at glassy carbon electrodes in aqueous (3:7 methanol: sodium acetate pH 4.3) electrolyte via potential sweeping, with an irreversible wave at Ep = 0.67 V vs. Ag/AgCl. The diffusion coefficient (D)
for the oxidation process was calculated as 1.43 × 10− 6 cm2 s
− 1 with αna = 0.7. DPA electrochemistry in a non
aqueous methanol/acetonitrile electrolyte resulted in a D value of 5.47 × 10− 8 cm2 s
− 1 with αna = 0.5. Electrochemical preparation of magnetic iron oxide nanoparticles was achieved via electrooxidation of an iron anode
in the presence of an amine surfactant followed by characterisation with SEM/EDX, XRD, FTIR and thermal
analysis. A surface confined layer of these magnetic nanoparticles served to positively influence the response to
DPA while impeding formation of surface confined oxidation products, with generation of an improved analytical
signal - sensitivity 1.13× 10− 3 A cm− 2 mM− 1 relative to bare electrode response (9.80 × 10− 4 A cm− 2 mM− 1
)
over the range 0.5–50 μM DPA using differential pulse voltammetry, with LOD 3.51 × 10− 6 M and LOQ 1.17 ×
10− 5 M. Real sample analysis involved recovery and differential pulse voltammetry of unburnt and burnt gunshot
residue with DPA qualitative and quantitative analysis.
Item Type: | Article |
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Keywords: | Magnetite; Fe3O4; Diphenylamine; Firearm residue; |
Academic Unit: | Faculty of Science and Engineering > Chemistry Faculty of Science and Engineering > Research Institutes > Human Health Institute |
Item ID: | 18264 |
Identification Number: | 10.1016/j.talanta.2021.123039 |
Depositing User: | Eithne Dempsey |
Date Deposited: | 12 Mar 2024 11:58 |
Journal or Publication Title: | Talanta |
Publisher: | Elsevier |
Refereed: | Yes |
Related URLs: | |
URI: | https://mu.eprints-hosting.org/id/eprint/18264 |
Use Licence: | This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here |
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