Detection of carbamate pesticides in vegetable samples using cholinesterase‐based biosensors

Abstract

Biosensors for determination of carbamates in vegetables based on five different cholinesterases as biorecognition elements and a screen-printed electrode system as an amperometric transducer were developed. Measurements were simply performed by dropping solutions (either sample or substrate) directly on the biosensor. The response of biosensors to selected carbamates (aldicarb, carbaryl, carbofuran, methomyl and propoxur) was characterized. The performance was evaluated on extracts of potatoes and carrots, the results from the AChE biosensor and a standard HPLC procedure were compared. Finally, the biosensor was used for the direct analysis of vegetable juices without any pretreatment steps. In this case, 10lg/L levels of added carbofuran and propoxur were reliably identified. The whole procedure takes less than 20min including 10 min incubation with samples. The concentrations of carbamates determined with biosensor agreed well for carbofuran. Lower response was observed for propoxur.

Rapid detection of neurotoxic insecticides in food using disposable acetylcholinesterase-biosensors and simple solvent extraction

“…The same amount of paraoxon in peach pap yielded a 14 % inhibition of AChE, -a 52 % recovery rate. Similar problems with low recovery rates in food samples were reported elsewhere [18,19,21]. Pogacnik et al obtained recovery rates of 51 % in apple juice and 60 % in orange juice for 10 µg/kg paraoxon [21].…”

“…reported recovery rates for carbofuran in potato juice [18,19]: 28 % for 10 µg/kg carbofuran, 34 % for 50 µg/kg carbofuran and 99 % for 125 µg/kg carbofuran. At higher concentrations up to 125 µg/kg propoxur in carrot juice the recovery rate remained below 70 %.…”

“…The few reports of cholinesterase-based biosensors for food testing either relied on laborious multi-step sample preparation or showed problems due to matrix effects reducing the accuracy of the results [17][18][19][20][21]. Furthermore, these tests were limited to carbamates and oxoforms of organophosphates although most of the found organophosphorus insecticides are sulfur-containing compounds, especially those with a P=S moiety (e.g.…”

Development, validation, and application of an acetylcholinesterase-biosensor test for the direct detection of insecticide residues in infant food

“…This test also avoids the use of any organic solvent and involves no pre-concentration step. In contrast to other biosensor tests, which showed reduced recovery rates in food (in most cases below 70 %) (Skladal et al, 1997;Nunes et al, 1998;Nunes et al, 1999;Pogacnik and Franko, 1999), the accuracy of the recoveries is very high, even at very low neurotoxin concentrations.…”

Mercaptobenzothiazole-on-Gold Organic Phase Biosensor Systems: 4. Effect of Organic Solvents on Organophosphate and Carbamate Pesticide Determination

“…This poses serious health effects for humans if water, processed food, fruits and vegetables with high concentrations of OPs and CMs are consumed. In children and infants it can lead to serious health effects such as as eye pain, abdominal pain, convulsions, respiratory failure, paralysis and even death (Kim et al, 2007;Liu et al, 2008;Sbai et al, 2007;Skladal et al, 1997). The toxicity of OPs and CMs are caused by their ability to bind irreversibly to the catalytic serine residue in acetylcholinesterase (AChE), which leads to inhibition of AChE that prevents nerve transmission by blocking the breakdown of the transmitter choline (Ch) (Somerset et al, 2009;Liu et al, 2008;Kim et al, 2007;Du et al, 2007;Kim et al, 2000).…”