Siripongpreda T.Noikorn N.Phookum T.Suea-Ngam A.Brack E.Ummartyotin S.Rodthongkum N.Mahidol University2025-08-032025-08-032025-09-01International Journal of Biological Macromolecules Vol.321 (2025)01418130https://repository.li.mahidol.ac.th/handle/123456789/111503The escalating environmental and public health threats posed by pesticide-contaminated water sources and underutilized cellulose-rich waste demand urgent sustainable solutions. This study presents an eco-friendly multiplex colorimetric sensing platform that concurrently addresses these dual challenges by repurposing recycled cellulose derived from recycled office paper. The system integrates a 3D-printed cassette with a semi-interpenetrating polymer network (semi-IPN) hydrogel synthesized from recycled cellulose and carboxymethyl cellulose (CMC). The hydrogel demonstrates exceptional water uptake (616 ± 6 % within 1 min), enhancing rapid analyte diffusion and sensor responsiveness. Enzyme-functionalized cellulose nanofibrils (CNFs) immobilized within the hydrogel enable simultaneous, sensitive detection of ethyl-paraoxon and carbaryl, achieving linear detection ranges of 0–1.5 ppm and 0–1.0 ppm, respectively, with high correlation coefficients (R² > 0.98). The platform exhibits vivid, naked-eye-readable color transitions across a broad pH spectrum (3−12), ensuring versatility in diverse environments. Validation using spiked tap water samples confirmed its practicality for on-site environmental monitoring, with recoveries aligning with regulatory standards. By transforming waste into a functional material, this work advances low-cost, portable analytical devices rooted in circular economy principles, offering a scalable model for sustainable technology development.Biochemistry, Genetics and Molecular BiologyArticleSCOPUS10.1016/j.ijbiomac.2025.1462102-s2.0-10501185992018790003