Bioactive microfluidic paper device for pesticide determination in waters Fernández Ramos, María Dolores Ogunneye, A. L. Barbarinde, N. A. A. Erenas Rodríguez, Miguel María Capitán Vallvey, Luis Fermín Microfluidic paper sensor µPAD Biosensor Pesticides Organophosphate and carbamate pesticides Water samples 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 acet- ylcholine 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 co- ordinate. 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 de- termination of pesticides in different water samples, with no sample preparation. 2020-07-02T08:56:54Z 2020-07-02T08:56:54Z 2020-05-11 journal article Talanta 218 (2020) 121108 http://hdl.handle.net/10481/62818 https://doi.org/10.1016/j.talanta.2020.121108 https://doi.org/10.5281/zenodo.3833041 eng http://creativecommons.org/licenses/by-nc-nd/3.0/es/ open access Atribución-NoComercial-SinDerivadas 3.0 España Elsevier