Pesticide analysis using nanoceria-coated paper-based devices as a detection platform

Abstract

We report the first use of a paper-based device coated with nanoceria as a simple, low-cost and rapid detection platform for the analysis of organophosphate (OP) pesticides using an enzyme inhibition assay with acetylcholinesterase (AChE) and choline oxidase (ChOX). In the presence of acetylcholine, AChE and ChOX catalyze the formation of H2O2, which is detected colorimetrically by a nanoceria-coated device resulting in the formation of a yellow color. After incubation with OP pesticides, the AChE activity was inhibited, producing less H2O2, and a reduction in the yellow intensity. The assay is able to analyze OP pesticides without the use of sophisticated instruments and gives detection limits of 18 ng mL(-1) and 5.3 ng mL(-1) for methyl-paraoxon and chlorpyrifos-oxon, respectively. The developed method was successfully applied to detect methyl-paraoxon in spiked vegetables (cabbage) and a dried seafood product (dried green mussel), obtaining ∼95% recovery values for both sample types. The spiked samples were also analyzed using LC-MS/MS as a comparison to the developed method and similar values were obtained, indicating that the developed method gives accurate results and is suitable for OP analysis in real samples.

Paper-based diagnostic devices for clinical paraquat poisoning diagnosis

“…[42][43][44] PADs as pesticide detection devices may use photoelectrochemical or colorimetric assay platforms to indicate the presence of organophosphorus or carbamate pesticides to secure food quality. [45][46][47] Notably, we, and others, have developed PADs to analyze serum organophosphate level for organophosphate poisoning in patients. 48 To the best of our knowledge, few previous studies have examined the use of PADs for clinically diagnostic PQ detection.…”

A Hybrid Lab-on-a-Chip Injector System for Autonomous Carbofuran Screening

“…Although it was not feasible to achieve LODs lower than EU MRLs (0.001 mg Kg −1 for apple), the platform is suitable to control the EU acute reference dose (ARfD), which can be exceeded under certain consumption conditions. Importantly, the attained performance improves the detection limit of colorimetric methods reported for other AChE inhibitors by between 4 times and 2 orders of magnitude [14,26,27]. Compared to chemiluminescent methods, which have been also used as screening tools, Liu et al [28] developed a paper-based chemiluminescence chip for dichlorvos monitoring in vegetables, detecting the analyte at ppm level, which is significantly higher than the developed method screening concentration.…”

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

“…To date, much analytical research has focused on the development and application of μPADs for food and water safety and quality monitoring; including fabrication procedures of the μPADs and suitable methods of detection for qualitative or quantitative interpretation of measurements. Fabrication usually entails the selection of a type of paper substrate before subjecting it to fabrication techniques such as cutting [ 20 , 21 , 22 , 23 , 24 , 25 ], inkjet printing [ 26 , 27 ], wax patterning [ 28 , 29 ], wax pencil drawing [ 30 ], wax printing [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ], screen printing [ 29 , 41 , 42 ], contact stamping [ 43 , 44 , 45 ], and photolithography [ 46 , 47 , 48 ]. Examples of μPADs fabricated using various methods and paper substrates are shown in Figure 1 .…”

“…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.…”