A new cysteamine-copper chemically modified screen-printed gold electrode for glyphosate determination

Alberti Giancarla; Camilla Zanoni; Daniele Merli; Lisa Rita Magnaghi; Raffaela Biesuz

doi:10.1016/j.talanta.2023.125436

A new cysteamine-copper chemically modified screen-printed gold electrode for glyphosate determination

Talanta. 2024 Mar 1:269:125436. doi: 10.1016/j.talanta.2023.125436. Epub 2023 Nov 23.

Authors

Alberti Giancarla¹, Camilla Zanoni², Daniele Merli², Lisa Rita Magnaghi³, Raffaela Biesuz³

Affiliations

¹ Department of Chemistry, University of Pavia, Via Taramelli 12, 27100, Pavia, Italy. Electronic address: giancarla.alberti@unipv.it.
² Department of Chemistry, University of Pavia, Via Taramelli 12, 27100, Pavia, Italy.
³ Department of Chemistry, University of Pavia, Via Taramelli 12, 27100, Pavia, Italy; Unità di Ricerca di Pavia, INSTM, Via G. Giusti 9, 50121, Firenze, Italy.

PMID: 38008026
DOI: 10.1016/j.talanta.2023.125436

Abstract

A chemically modified screen-printed gold electrode has been prepared by covering the electrode surface with a cysteamine-copper self-assembled monolayer (SAM). The sensor was effective for the voltammetric sensing of glyphosate. The method exploits the interaction of glyphosate with copper ions complexed by cysteamine, which results in a decrease in the intensity of copper redox current. Cyclic voltammetry was employed as a measuring technique. When dealing with voltammograms with numerous peaks changing in shape and size, it is difficult to define which signal is the most significant for the analyte determination; in these cases, a helpful approach is chemometrics. In this work, PLS (Partial Least Square regression) has been applied to build models to correlate the signal with the glyphosate concentration in standard aqueous solutions and tap water samples (matrix-matched calibration). The method's figures of merits were evaluated, obtaining a limit of quantification of about 5 μM. The reliability of the proposed sensor was verified by analyzing tap water spiked with glyphosate; recoveries higher than 90 % were achieved.

Keywords: Chemically modified electrodes (CME); Cysteamine-copper complexes; Glyphosate; Partial least square regression (PLS); Thiol self assembled monolayer (SAM); Voltammetric screen-printed cell.