Development of a New Screen-Printed Transducer for the Electrochemical Detection of Thiram

David Ibáñez,Pablo Fanjul-Bolado,María Begoña González-García,Daniel Izquierdo-Bote,David Hernández-Santos

doi:10.3390/chemosensors9110303

David Ibáñez, Pablo Fanjul-Bolado + Show 3 more

Open Access

https://doi.org/10.3390/chemosensors9110303

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Journal: Chemosensors	Publication Date: Oct 25, 2021
Citations: 9	License type: CC BY 4.0

Affiliation: Metrohm Dropsens (Spain)

Abstract

A new transducer based on a screen-printed carbon electrode has been developed for the quantification of thiram. Detection of this fungicide is based on the performance of two enzymes: (1) aldehyde dehydrogenase catalyzes the aldehyde oxidation using NAD+ as a cofactor and simultaneously, (2) diaphorase reoxidizes the NADH formed in the first enzymatic process due to the presence of hexacyanoferrate(III) which is reduced to hexacyanoferrate(II). Taking into account that aldehyde dehydrogenase is inhibited by thiram, the current decreases with pesticide concentration and thiram can be electrochemically quantified below legal limits. The transducer proposed in this work involves the modification of the carbon WE with the co-factors (NAD+ and hexacyanoferrate(III)) required in the enzymatic system. The new device employed in this work allows the detection of 0.09 ppm thiram, a concentration below legal limits (Maximum Residue Limits 0.1–10 ppm).

Highlights

Dithiocarbamate fungicides are one of the most important pesticides currently used in the control of a huge variety of diseases on seeds, fruits and vegetables
Their Maximum Residue Limits (MRLs) are limited in the range of ppm or even some dithiocarbamate pesticides are forbidden in several countries
MRLs of thiram in food for human and animal consumption are established by the European Union (EU) from 0.1 to 10 ppm depending on the food product [7]

Summary

Introduction

Dithiocarbamate fungicides (thiram, ziram, mancozeb, maneb, zineb, etc.) are one of the most important pesticides currently used in the control of a huge variety of diseases on seeds, fruits and vegetables. Several studies relate this family of fungicide to health diseases such as Parkinson [1,2,3], teratogenesis [4] and carcinogenesis [5]. Due to their toxicity, their Maximum Residue Limits (MRLs) are limited in the range of ppm or even some dithiocarbamate pesticides are forbidden in several countries. MRLs of thiram in food for human and animal consumption are established by the European Union (EU) from 0.1 to 10 ppm depending on the food product [7]

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