Towards direct detection of tetracycline residues in milk with a gold nanostructured electrode

Raykova, M. R., McGuire, K. , Peveler, W. J. , Corrigan, D. K., Henriquez, F. L. and Ward, A. C. (2023) Towards direct detection of tetracycline residues in milk with a gold nanostructured electrode. PLoS ONE, 18(6), e0287824. (doi: 10.1371/journal.pone.0287824) (PMID:37368910) (PMCID:PMC10298779)

Abstract

Tetracycline antibiotics are used extensively in veterinary medicine, but the majority of the administrated dose is eliminated unmodified from the animal through various excretion routes including urine, faeces and milk. In dairy animals, limits on residues secreted in milk are strictly controlled by legislation. Tetracyclines (TCs) have metal chelation properties and form strong complexes with iron ions under acidic conditions. In this study, we exploit this property as a strategy for low cost, rapid electrochemical detection of TC residues. TC-Fe(III) complexes in a ratio of 2:1 were created in acidic conditions (pH 2.0) and electrochemically measured on plasma-treated gold electrodes modified with electrodeposited gold nanostructures. DPV measurements showed a reduction peak for the TC-Fe(III) complex that was observed at 50 mV (vs. Ag/AgCl QRE). The limit of detection in buffer media was calculated to be 345 nM and was responsive to increasing TC concentrations up to 2 mM, added to 1 mM FeCl3. Whole milk samples were processed to remove proteins and then spiked with tetracycline and Fe(III) to explore the specificity and sensitivity in a complex matrix with minimal sample preparation, under these conditions the LoD was 931 nM. These results demonstrate a route towards an easy-to-use sensor system for identification of TC in milk samples taking advantage of the metal chelating properties of this antibiotic class.

• Item Type: Articles
• Additional Information: This research was funded in part by the Engineering & Physical Sciences Research Council (EPSRC) [EP/T517938/1], and through a Scottish Universities Life Sciences Alliance Technology Seed Award.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Peveler, Dr William and McGuire, Katie

Creator Roles

McGuire, K.: Writing – review and editing
Peveler, W. J.: Writing – review and editing

• Authors: Raykova, M. R., McGuire, K., Peveler, W. J., Corrigan, D. K., Henriquez, F. L., and Ward, A. C.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: PLoS ONE
• Publisher: Public Library of Science
• ISSN: 1932-6203
• ISSN (Online): 1932-6203
• Copyright Holders: Copyright © 2023 Raykova et al.
• First Published: First published in PLoS ONE 18(6): e0287824
• Publisher Policy: Reproduced under a Creative Commons License