Bioactive Paper Sensor Based on the Acetylcholinesterase for the Rapid Detection of Organophosphate and Carbamate Pesticides

Abstract

In many countries, people are becoming more concerned about pesticide residues which are present in or on food and feed products. For this reason, several methods have been developed to monitor the pesticide residue levels in food samples. In this study, a bioactive paper-based sensor was developed for detection of acetylcholinesterase (AChE) inhibitors including organophosphate and carbamate pesticides. Based on the Ellman colorimetric assay, the assay strip is composed of a paper support (1 × 10 cm), onto which a biopolymer chitosan gel immobilized in crosslinking by glutaraldehyde with AChE and 5,5′-dithiobis(2-nitrobenzoic) acid (DTNB) and uses acetylthiocholine iodide (ATChI) as an outside reagent. The assay protocol involves introducing the sample to sensing zone via dipping of a pesticide-containing solution. Following an incubation period, the paper is placed into ATChI solution to initiate enzyme catalyzed hydrolysis of the substrate, causing a yellow color change. The absence or decrease of the yellow color indicates the levels of the AChE inhibitors. The biosensor is able to detect organophosphate and carbamate pesticides with good detection limits (methomyl = 6.16 × 10−4 mM and profenofos = 0.27 mM) and rapid response times (~5 min). The results show that the paper-based biosensor is rapid, sensitive, inexpensive, portable, disposable, and easy-to-use.

The end user sensor tree: An end-user friendly sensor database

“…Compared to optical methods however EC is rarely used for non-expert sensors while colorimetric are gaining traction due to easy visual interpretation of the results generated. Cholinesterase inhibition assays in dipstick format (Badawy and El-Aswad, 2014) (Apilux et al, 2015) or immunochromatographic assays (Fang et al, 2015) for pesticides are good examples despite the fact they lack quantification. This could be altered if a smartphone camera is used as a detector which has been the case for both pesticides (Comina et al, 2016) and mycotoxins (Machado et al, 2018).…”

Advances in Microfluidic Paper-Based Analytical Devices for Food and Water Analysis

“…Whatman filter paper grade 1, on the other hand, has been the most commonly used paper substrate for μPAD fabrication in food and water analysis [ 25 , 30 , 32 , 34 , 35 , 36 , 41 , 45 , 51 , 52 , 53 , 54 ]. Paper substrates that have been similarly utilized include Whatman chromatography paper 3 MM Chr [ 20 , 21 ], Whatman filter paper grade 4 [ 42 , 55 ], Whatman RC60 regenerated cellulose membrane filter [ 56 ], Millipore MCE membrane filter [ 57 ], Canson paper [ 58 ], Fisherbrand P5 filter paper [ 59 ], JProLab JP 40 filter paper [ 44 ], Advantec 51B chromatography paper [ 48 ], and Ahlstrom 319 paper [ 39 ]. Although comparing the capabilities of each paper substrate is inappropriate when different fabrication methods and detection methods are employed among the studies, some comparisons of substrates have been made.…”

Preparation of ferrocene core dendrimers and immobilization of AChE for detection of diclofop-methyl herbicide

“…Herbicides disrupt the hormonal balance that regulates plant metabolism, such as cell division, cell elongation, protein synthesis and respiration [14]. Therefore, determination of these substances is vital [15,16]. Gas chromatography (GC) and high-performance liquid chromatography (HPLC) are common methods used in the detection of diclofop-methyl.…”