Bioactive microfluidic paper device for pesticide determination in waters

Abstract

This work presents a new optical microfluidic paper biosensor for the detection of organophosphate pesticides and carbamate pesticides. The assay strip is composed of a paper support (1×17.6 mm) onto which acetylcholine esterase (AChE) and acetylcholine chloride (AChCl) are deposited, in such a way that there is a small hole between them that ensures that they only come into contact in the reaction zone when they are carried by a solution of the sample by lateral flow to the reaction zone containing bromocresol purple (BCP) as the pH indicator, immobilized by sol-gel. The sensor operates at room temperature and the rate of the inhibited reaction serves as an analytical signal, which is measured using a camera by quantifying the appropriate colour coordinate. Calibration curves were obtained for chlorpyrifos and carbaryl, with a useful concentration range from 0.24 to 20 µg•L -1 for carbaryl and from 2.00 to 45 µg•L -1 for chlorpyrifos. The detection limits were 0.24 and 2.00 µg•L -1 , respectively, and with reproducibility around 4.2-5.5%. The method was applied to the determination of pesticides in different water samples, with no sample preparation.

A Simple Counting-Based Measurement for Paper Analytical Devices and Their Application

“…Therefore, our device can combine both high efficiency and convenience for rapid screening of lower CBR in the samples, especially with the lower concentration of their MAC being at 0.09 μg/mL, which is relative to the counting signal at 9.0 lines on cPADs. Our proposed azo-coupling reaction on the cPADs for CBR monitoring is comparable with other colorimetric methods described and shown in Table S1. ,− With these characteristics, our cPADs can truly be potential screening tools for onsite analysis without a skilled person.…”

Lab-on-a-chip technologies for food safety, processing, and packaging applications: a review

“…Reproducibility obtained was 4.2–5%. No specific sample preparation was required Fernández-Ramos et al ( 2020 ) ELISA LOC Generally performed on a microplate. The target solution continuously flows into the microchannel.…”

Acetylcholinesterase Immobilized on Glass Rod for Organophosphorus Pesticides Detection: Application on Milk Analysis

“…AChE hydrolyzes acetylcholine into choline and acetic acid leading to a decreasing pH of the medium and can be determined by changing of color of an indicator. Several spectrophotometric indicators like cresol red, phenol red, bromocresol purple, and others have been used for pesticide detection [20]. The authors [21] used as an optical biosensor based on a lipophilic chromoionophore doped on sol-gel films for determination of AChE inhibition caused by dichlorvos; fluorescent pH-sensitive dye in PVC gel matrix was used in the fabrication of biosensor [13], and authors [22] design a biosensor with AChE and bromothymol blue in gel film.…”