{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T05:14:11Z","timestamp":1783574051274,"version":"3.55.0"},"reference-count":115,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,6,26]],"date-time":"2026-06-26T00:00:00Z","timestamp":1782432000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Jilin Province Science and Technology Development Plan Project","award":["20240303047NC"],"award-info":[{"award-number":["20240303047NC"]}]},{"name":"Science and Technology Research Project of the Jilin Provincial Department of Education","award":["JJKH20230077KJ"],"award-info":[{"award-number":["JJKH20230077KJ"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Micromachines"],"abstract":"<jats:p>Heavy metal ion pollution has emerged as a global issue. These contaminants are not only present in water sources but are also commonly detected in air, soil, food, and consumer products, posing serious risks to ecosystems and human health. Even at very low concentrations, heavy metal ions can exhibit substantial toxicity. Traditional methods for the detection of heavy metal ions typically require complex laboratory equipment and specialized technicians, making them inadequate for rapid on-site monitoring. Microfluidic technology, as an innovative platform capable of precisely controlling and manipulating minute volumes of fluid, has demonstrated enormous potential in analytical chemistry, biomedicine, and environmental monitoring. In the rapidly developing field of microfluidics, paper-based microfluidic platforms have become prominent due to their low cost, straightforward fabrication, and eco-friendly nature, offering powerful tools for the detection of heavy metal ions in diverse samples. This survey consolidates the major advances reported from 2015 to 2025 in utilizing paper-based microfluidic systems for identifying heavy metal ion pollutants in diverse sample types, including air, explosive residues, water sources, herbal supplements, skin-whitening cosmetics, environmental aerosols, urine, soil, gunshot residues, cucumber plants, and food. The review analyzes in detail the principles and applications of detection strategies based on colorimetric methods, fluorescent methods, electrochemical methods, dual-detection systems, and other methods, as well as the role of nanomaterials and selective recognition elements in improving detection sensitivity and specificity. These portable, low-cost, and easy-to-operate detection systems provide viable solutions for environmental and public health monitoring, particularly suitable for resource-limited regions and scenarios requiring rapid detection.<\/jats:p>","DOI":"10.3390\/mi17070780","type":"journal-article","created":{"date-parts":[[2026,6,30]],"date-time":"2026-06-30T05:58:04Z","timestamp":1782799084000},"page":"780","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Recent Advances in Paper-Based Microfluidic Devices for Heavy Metal Ion Detection: A Review"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-1275-9178","authenticated-orcid":false,"given":"Jianqin","family":"Xu","sequence":"first","affiliation":[{"name":"School of Basic Medical Sciences, Beihua University, Jilin City 132013, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xinyuan","family":"Ma","sequence":"additional","affiliation":[{"name":"School of Stomatology, Shanxi Medical University, Taiyuan 030001, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhiping","family":"Li","sequence":"additional","affiliation":[{"name":"Jilin City People\u2019s Hospital, Jilin City 132011, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tingting","family":"Zhou","sequence":"additional","affiliation":[{"name":"College of Medical Technology, Beihua University, Jilin City 132013, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yanshuang","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Basic Medical Sciences, Beihua University, Jilin City 132013, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-0494-7685","authenticated-orcid":false,"given":"Jianyu","family":"Zhu","sequence":"additional","affiliation":[{"name":"School of Basic Medical Sciences, Beihua University, Jilin City 132013, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"178870","DOI":"10.1016\/j.scitotenv.2025.178870","article-title":"Assessment of ecological risks and spatiotemporal monitoring of heavy metal contamination in cultivated soils of the Liaohe River Basin, Jilin Province, China","volume":"968","author":"Chen","year":"2025","journal-title":"Sci. Total Environ."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"7518","DOI":"10.1038\/s41598-025-91453-7","article-title":"Comprehensive assessment of heavy metal contamination and associated health risks in agricultural soils and groundwater proximal to industrial sites","volume":"15","author":"Sharafi","year":"2025","journal-title":"Sci. Rep."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"144","DOI":"10.1007\/s11270-025-07759-9","article-title":"A decade review of human health risks from heavy metal contamination in industrial sites","volume":"236","author":"Han","year":"2025","journal-title":"Water Air Soil Pollut."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"14750","DOI":"10.1038\/s41598-025-98809-z","article-title":"Heavy metal pollution migration and its ecological impact on microbial communities in the karst region of Guangxi","volume":"15","author":"Ji","year":"2025","journal-title":"Sci. Rep."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Wang, X., Han, X., Guo, S., Ma, Y., and Zhang, Y. (2024). Associations between patterns of blood heavy metal exposure and health outcomes: Insights from NHANES 2011\u20132016. BMC Public Health, 24.","DOI":"10.1186\/s12889-024-17754-0"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Acharya, S. (2024). Heavy metal contamination in food: Sources, impact, and remedy. Food Safety and Quality in the Global South, Springer Nature Singapore.","DOI":"10.1007\/978-981-97-2428-4_8"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Shi, Y., Zhang, S., Zhou, H., Dong, Y., Liu, G., Ye, W., He, R., and Zhao, G. (2025). Recent developments in heavy metals detection: Modified electrodes, pretreatment methods, prediction models and algorithms. Metals, 15.","DOI":"10.3390\/met15010080"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Manousi, N., and Zachariadis, G.A. (2021). Development and validation of an ICP-AES method for the determination of toxic and nutrient metals in candies: Application for the analysis of different samples from the Greek market. Appl. Sci., 11.","DOI":"10.3390\/app112210599"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"204","DOI":"10.1021\/es9502482","article-title":"Comparison of AAS, ICP-AES, PSA, and XRF in determining lead and cadmium in soil","volume":"30","author":"Pyle","year":"1995","journal-title":"Environ. Sci. Technol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"115","DOI":"10.33176\/AACB-19-00024","article-title":"Inductively coupled plasma mass spectrometry: Introduction to analytical aspects","volume":"40","author":"Wilschefski","year":"2019","journal-title":"Clin. Biochem. Rev."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"11737","DOI":"10.1016\/j.saa.2019.117370","article-title":"A spectrophotometric method for simultaneous determination of trace ions of copper, cobalt, and nickel in the zinc sulfate solution by ultraviolet-visible spectrometry","volume":"223","author":"Zhou","year":"2019","journal-title":"Spectrochim. Acta A Mol. Biomol. Spectrosc."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"118004","DOI":"10.1016\/j.trac.2024.118004","article-title":"A review on recent advances of AI-integrated microfluidics for analytical and bioanalytical applications","volume":"181","author":"Asadian","year":"2024","journal-title":"TrAC Trends Anal. Chem."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Filippidou, M.K., and Chatzandroulis, S. (2023). Microfluidic devices for heavy metal ions detection: A review. Micromachines, 14.","DOI":"10.3390\/mi14081520"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2400155","DOI":"10.1002\/smtd.202400155","article-title":"Advances in microfluidic paper-based analytical devices (\u00b5PADs): Design, fabrication, and applications","volume":"8","author":"Chen","year":"2024","journal-title":"Small Methods"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Aryal, P., and Henry, C.S. (2024). Advancements and challenges in microfluidic paper-based analytical devices: Design, manufacturing, sustainability, and field applications. Front. Lab Chip Technol., 3.","DOI":"10.3389\/frlct.2024.1467423"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Kumar, S., Kaushal, J.B., and Lee, H.P. (2024). Sustainable sensing with paper microfluidics: Applications in health, environment, and food safety. Biosensors, 14.","DOI":"10.20944\/preprints202405.0924.v1"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1016\/j.bios.2015.09.038","article-title":"Paper-based chemical and biological sensors: Engineering aspects","volume":"77","author":"Ahmed","year":"2016","journal-title":"Biosens. Bioelectron."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"106699","DOI":"10.1016\/j.microc.2021.106699","article-title":"An overview of the recent developments of microfluidic paper-based analytical devices for the detection of chromium species","volume":"170","author":"Alahmad","year":"2021","journal-title":"Microchem. J."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Zacharis, C.K. (2026). Paper-based analytical devices coupled with fluorescence detection and smartphone imaging: Advances and applications. Sensors, 26.","DOI":"10.3390\/s26031012"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1880","DOI":"10.1021\/acs.analchem.0c04247","article-title":"Heavy metals detection with paper-based electrochemical sensors","volume":"93","author":"Ding","year":"2021","journal-title":"Anal. Chem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"540","DOI":"10.3390\/biomedicines9050540","article-title":"Advanced signal-amplification strategies for paper-based analytical devices: A comprehensive review","volume":"9","author":"Hoang","year":"2021","journal-title":"Biomedicines"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"116748","DOI":"10.1016\/j.trac.2022.116748","article-title":"Aptamers functionalized metal and metal oxide nanoparticles: Recent advances in heavy metal monitoring","volume":"157","author":"Sawan","year":"2022","journal-title":"TrAC Trends Anal. Chem."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2210","DOI":"10.1039\/c3lc50169h","article-title":"Paper-based microfluidic point-of-care diagnostic devices","volume":"13","author":"Yetisen","year":"2013","journal-title":"Lab Chip"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"5820","DOI":"10.1021\/acs.analchem.3c00378","article-title":"Capillary flow-driven microfluidics combined with a paper device for fast user-friendly detection of heavy metals in water","volume":"95","author":"Aryal","year":"2023","journal-title":"Anal. Chem."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Rauf, M.F., and Lin, Z. (2025). Innovative microfluidic technologies for rapid heavy metal ion detection. Chemosensors, 13.","DOI":"10.3390\/chemosensors13040149"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1039\/C0AN00406E","article-title":"A low-cost, simple, and rapid fabrication method for paper-based microfluidics using wax screen-printing","volume":"136","author":"Dungchai","year":"2011","journal-title":"Analyst"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"103263","DOI":"10.1016\/j.mtcomm.2022.103263","article-title":"Inkjet-printed flexible sensors: From function materials, manufacture process, and applications perspective","volume":"31","author":"Wang","year":"2022","journal-title":"Mater. Today Commun."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"5294","DOI":"10.1002\/anie.201411508","article-title":"Paper-based inkjet-printed microfluidic analytical devices","volume":"54","author":"Yamada","year":"2015","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"6580","DOI":"10.1039\/C4AN01624F","article-title":"One-step polymer screen-printing for microfluidic paper-based analytical device (\u00b5PAD) fabrication","volume":"139","author":"Sameenoi","year":"2014","journal-title":"Analyst"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Mahmud, M.A., Blondeel, E.J.M., Kaddoura, M., and MacDonald, B.D. (2018). Features in microfluidic paper-based devices made by laser cutting: How small can they be?. Micromachines, 9.","DOI":"10.3390\/mi9050220"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"29797","DOI":"10.1039\/D0RA04301J","article-title":"Fabrication of paper microfluidic devices using a toner laser printer","volume":"10","author":"Ng","year":"2020","journal-title":"RSC Adv."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"113991","DOI":"10.1016\/j.sna.2022.113991","article-title":"Engineering a monolithic 3D paper-based analytical device (\u00b5PAD) by stereolithography 3D printing and sequential digital masks for efficient 3D mixing and dopamine detection","volume":"347","author":"Zaki","year":"2022","journal-title":"Sens. Actuators A Phys."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"8772","DOI":"10.1021\/ac202290d","article-title":"\u03b2-Galactosidase-based colorimetric paper sensor for determination of heavy metals","volume":"83","author":"Hossain","year":"2011","journal-title":"Anal. Chem."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1016\/j.aca.2015.04.014","article-title":"Development of paper-based microfluidic analytical device for iron assay using photomask printed with 3D printer for fabrication of hydrophilic and hydrophobic zones on paper by photolithography","volume":"883","author":"Asano","year":"2015","journal-title":"Anal. Chim. Acta"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"71","DOI":"10.2116\/analsci.34.71","article-title":"Microfluidic paper-based analytical device for the determination of hexavalent chromium by photolithographic fabrication using a photomask printed with 3D printer","volume":"34","author":"Asano","year":"2018","journal-title":"Anal. Sci."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"31","DOI":"10.2116\/analsci.32.31","article-title":"Determination of iron ion in the water of a natural hot spring using microfluidic paper-based analytical devices","volume":"32","author":"Ogawa","year":"2016","journal-title":"Anal. Sci."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"518","DOI":"10.1016\/j.talanta.2019.06.006","article-title":"A paper-based microfluidic analytical device combined with home-made SPE column for the colorimetric determination of copper(II) ion","volume":"204","author":"Wu","year":"2019","journal-title":"Talanta"},{"key":"ref_38","first-page":"100210","article-title":"A prototype microfluidic paper-based chromatic device for simultaneous determination of copper(II) and zinc(II) in urine","volume":"7","year":"2023","journal-title":"Talanta Open"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"110854","DOI":"10.1016\/j.dyepig.2022.110869","article-title":"A novel spirooxazine derivative as a colorimetric probe for Fe2+ and Pb2+ determination on microfluidic paper-based analytical device (\u00b5PAD) for maintaining in photochromic efficiency","volume":"208","author":"Khunkhong","year":"2023","journal-title":"Dye. Pigment."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1016\/j.forc.2018.03.008","article-title":"Simultaneous colorimetric detection of metallic salts contained in low explosives residue using a microfluidic paper-based analytical device (\u00b5PAD)","volume":"9","author":"Chabaud","year":"2018","journal-title":"Forensic Chem."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"585","DOI":"10.2116\/analsci.20P325","article-title":"Remote investigation of total chromium determination in environmental samples of the Kombolcha Industrial Zone, Ethiopia, using microfluidic paper-based analytical devices","volume":"37","author":"Muhammed","year":"2021","journal-title":"Anal. Sci."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"085214","DOI":"10.1063\/1.4999784","article-title":"Visual quantification of Hg on a microfluidic paper-based analytical device using distance-based detection technique","volume":"7","author":"Cai","year":"2017","journal-title":"AIP Adv."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"83","DOI":"10.2116\/analsci.34.83","article-title":"Microfluidic paper-based analytical device for quantification of lead using reaction band-length for identification of bullet hole and its potential for estimating firing distance","volume":"34","author":"Buking","year":"2018","journal-title":"Anal. Sci."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"032007","DOI":"10.1088\/1757-899X\/546\/3\/032033","article-title":"Microfluidic paper-based analytical devices (\u00b5PADs) for analysis lead using naked eye and colorimetric detections","volume":"546","author":"Wisang","year":"2019","journal-title":"IOP Conf. Ser. Mater. Sci. Eng."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1038\/s41378-019-0123-9","article-title":"Detection and extraction of heavy metal ions using paper-based analytical devices fabricated via atom stamp printing","volume":"6","author":"Guan","year":"2020","journal-title":"Microsyst. Nanoeng."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"36142","DOI":"10.1039\/D4RA05358C","article-title":"Distance-based paper microfluidic devices for rapid visual quantification of heavy metals in herbal supplements and cosmetics","volume":"14","author":"Manmana","year":"2024","journal-title":"RSC Adv."},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Chowdury, M.A., Walji, N., Mahmud, M.A., and MacDonald, B.D. (2017). Paper-based microfluidic device with a gold nanosensor to detect arsenic contamination of groundwater in Bangladesh. Micromachines, 8.","DOI":"10.3390\/mi8030071"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"116732","DOI":"10.1016\/j.molliq.2021.117020","article-title":"Application of CysA@AuNPs supported amino acids towards rapid and selective identification of Hg(II) and Cu(II) ions in aqueous solution: An innovative microfluidic paper-based (\u00b5PADs) colorimetric sensing platform","volume":"338","author":"Abdollahiyan","year":"2021","journal-title":"J. Mol. Liq."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"115511","DOI":"10.1016\/j.measurement.2024.115519","article-title":"Integration of LSPR-based colorimetric sensing and smartphone-assisted dual read-out microfluidic paper-based analytical devices for rapid detection of Pb2+ in environmental samples","volume":"239","author":"Rasheed","year":"2025","journal-title":"Measurement"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1016\/j.talanta.2016.04.037","article-title":"Chromatic analysis by monitoring unmodified silver nanoparticles reduction on double layer microfluidic paper-based analytical devices for selective and sensitive determination of mercury(II)","volume":"155","author":"Meelapsom","year":"2016","journal-title":"Talanta"},{"key":"ref_51","doi-asserted-by":"crossref","unstructured":"Fu, L.M., Shih, M.K., Hsieh, C.W., Ju, W.J., Tain, Y.L., Cheng, K.C., Hsu, J.H., Chen, Y.W., and Hou, C.Y. (2021). Design of an integrated microfluidic paper-based chip and inspection machine for the detection of mercury in food with silver nanoparticles. Biosensors, 11.","DOI":"10.3390\/bios11120491"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"21836","DOI":"10.1039\/D2RA02820D","article-title":"Colorimetric and naked-eye detection of arsenic(III) using a paper-based microfluidic device decorated with silver nanoparticles","volume":"12","author":"Saadati","year":"2022","journal-title":"RSC Adv."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"114","DOI":"10.1016\/j.aca.2020.06.006","article-title":"A 3D origami paper-based analytical device combined with PVC membrane for colorimetric assay of heavy metal ions: Application to determination of Cu(II) in water samples","volume":"1126","author":"Sharifi","year":"2020","journal-title":"Anal. Chim. Acta"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"3339","DOI":"10.1007\/s00216-021-03274-y","article-title":"Speciation of chromium in water samples using microfluidic paper-based analytical devices with online oxidation of trivalent chromium","volume":"413","author":"Muhammed","year":"2021","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"429","DOI":"10.1007\/s13206-020-4407-9","article-title":"Simultaneous multiplexed detection of protein and metal ions by a colorimetric microfluidic paper-based analytical device","volume":"14","author":"Xiong","year":"2020","journal-title":"BioChip J."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"2555","DOI":"10.1021\/acs.analchem.5b00040","article-title":"\u201cPeriodic-table-style\u201d paper device for monitoring heavy metals in water","volume":"87","author":"Li","year":"2015","journal-title":"Anal. Chem."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/j.snb.2018.06.005","article-title":"A chemically functionalized paper-based microfluidic platform for multiplex heavy metal detection","volume":"273","author":"Devadhasan","year":"2018","journal-title":"Sens. Actuators B Chem."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"2229","DOI":"10.1039\/D0AN02200D","article-title":"Highly selective simultaneous determination of Cu(II), Co(II), Ni(II), Hg(II), and Mn(II) in water samples using microfluidic paper-based analytical devices","volume":"146","author":"Kamnoet","year":"2021","journal-title":"Analyst"},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"426","DOI":"10.1016\/j.talanta.2017.09.059","article-title":"Improved assessment of accuracy and performance using a rotational paper-based device for multiplexed detection of heavy metals","volume":"178","author":"Sun","year":"2018","journal-title":"Talanta"},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"344031","DOI":"10.1016\/j.aca.2025.344031","article-title":"Smartphone-assisted dual-sided capillary microfluidic device for multiplex detection of heavy metals and nutrients in drinking water","volume":"1356","author":"Punnoy","year":"2025","journal-title":"Anal. Chim. Acta"},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"e00456","DOI":"10.1016\/j.ohx.2023.e00456","article-title":"Microfluidic paper-based device coupled with 3D printed imaging box for colorimetric detection in resource-limited settings","volume":"15","author":"Vaishampayan","year":"2023","journal-title":"HardwareX"},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"020078","DOI":"10.1063\/5.0100849","article-title":"Paper-based microfluidic device coupled with Foldscope for the detection of As3+ ions using gold nanoparticles","volume":"2427","author":"Gabhane","year":"2023","journal-title":"AIP Conf. Proc."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"46696","DOI":"10.1021\/acsomega.5c03844","article-title":"Mass production and outside test of microfluidic paper based analysis devices for determining chromium ions in industrial wastewater","volume":"10","author":"Yao","year":"2025","journal-title":"ACS Omega"},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"134732","DOI":"10.1016\/j.snb.2023.134732","article-title":"Pb(II) inhibits CRISPR\/Cas12a activation and application for paper-based microfluidic biosensor assisted by smartphone","volume":"398","author":"Zhang","year":"2024","journal-title":"Sens. Actuators B Chem."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1038\/s41378-018-0044-z","article-title":"Graphene oxide nanosheets coupled with paper microfluidics for enhanced on-site airborne trace metal detection","volume":"5","author":"Sun","year":"2019","journal-title":"Microsyst. Nanoeng."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"110","DOI":"10.1016\/j.aca.2018.07.053","article-title":"Multiplex quantification of metals in airborne particulate matter via smartphone and paper-based microfluidics","volume":"1044","author":"Sun","year":"2018","journal-title":"Anal. Chim. Acta"},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"139041","DOI":"10.1016\/j.snb.2025.139041","article-title":"A foldable and paper-based microfluidic device integrated with LIBS and colorimetric for accurate heavy metals detection","volume":"448","author":"Ma","year":"2026","journal-title":"Sens. Actuators B Chem."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"6497","DOI":"10.1007\/s00216-019-02032-5","article-title":"Three-dimensional microfluidic paper-based device for multiplexed colorimetric detection of six metal ions combined with use of a smartphone","volume":"411","author":"Li","year":"2019","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1007\/s10311-019-00921-w","article-title":"Determination of Cr(III) and Cr(VI) in water by dual-gel electromembrane extraction and a microfluidic paper-based device","volume":"18","author":"Tabani","year":"2020","journal-title":"Environ. Chem. Lett."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"4438","DOI":"10.1039\/C8AY01331D","article-title":"Aptamer-based colorimetric determination of Pb2+ using a paper-based microfluidic platform","volume":"10","author":"Fakhri","year":"2018","journal-title":"Anal. Methods"},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"31948","DOI":"10.1038\/srep31948","article-title":"A simple paper-based colorimetric device for rapid mercury(II) assay","volume":"6","author":"Chen","year":"2016","journal-title":"Sci. Rep."},{"key":"ref_72","doi-asserted-by":"crossref","unstructured":"Nashukha, H.L., Sitanurak, J., Sulistyarti, H., Nacapricha, D., and Uraisin, K. (2021). Simple and equipment-free paper-based device for determination of mercury in contaminated soil. Molecules, 26.","DOI":"10.3390\/molecules26072004"},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"7823","DOI":"10.1039\/C5AN01016K","article-title":"Rapid detection of Cu2+ by a paper-based microfluidic device coated with bovine serum albumin (BSA)\u2013Au nanoclusters","volume":"140","author":"Fang","year":"2015","journal-title":"Analyst"},{"key":"ref_74","doi-asserted-by":"crossref","unstructured":"Han, J., Liu, H., Qi, J., Xiang, J., Fu, L., Sun, X., Wang, L., Wang, X., Li, B., and Chen, L. (2023). A simple and effective visual fluorescent sensing paper-based chip for the ultrasensitive detection of mercury ions in environmental water. Sensors, 23.","DOI":"10.3390\/s23063094"},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1016\/j.bios.2014.12.042","article-title":"A low-cost and simple paper-based microfluidic device for simultaneous multiplex determination of different types of chemical contaminants in food","volume":"68","author":"Zhang","year":"2015","journal-title":"Biosens. Bioelectron."},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"592","DOI":"10.1039\/C8NA00080H","article-title":"Nitrogen-doped carbon dots as fluorescence on\u2013off\u2013on sensor for parallel detection of copper(II) and mercury(II) ions in solutions as well as in filter paper-based microfluidic device","volume":"1","author":"Patir","year":"2019","journal-title":"Nanoscale Adv."},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"112158","DOI":"10.1016\/j.diamond.2025.112158","article-title":"Blue fluorescent carbon nanoparticles as sensor probe and paper based microfluidic device for Hg2+ ion detection","volume":"154","author":"Singh","year":"2025","journal-title":"Diam. Relat. Mater."},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"224","DOI":"10.1016\/j.snb.2017.05.052","article-title":"Three-dimensional paper-based microfluidic chip device for multiplexed fluorescence detection of Cu2+ and Hg2+ ions based on ion imprinting technology","volume":"251","author":"Qi","year":"2017","journal-title":"Sens. Actuators B Chem."},{"key":"ref_79","doi-asserted-by":"crossref","first-page":"128196","DOI":"10.1016\/j.jhazmat.2021.128165","article-title":"A rotary multi-positioned cloth\/paper hybrid microfluidic device for simultaneous fluorescence sensing of mercury and lead ions by using ion imprinted technologies","volume":"428","author":"Wang","year":"2022","journal-title":"J. Hazard. Mater."},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"127462","DOI":"10.1016\/j.snb.2019.127462","article-title":"ZnSe quantum dot based ion imprinting technology for fluorescence detecting cadmium and lead ions on a three-dimensional rotary paper-based microfluidic chip","volume":"305","author":"Zhou","year":"2020","journal-title":"Sens. Actuators B Chem."},{"key":"ref_81","doi-asserted-by":"crossref","first-page":"3299","DOI":"10.1007\/s00216-021-03269-9","article-title":"A three-dimensional pinwheel-shaped paper-based microfluidic analytical device for fluorescence detection of multiple heavy metals in coastal waters by rational device design","volume":"413","author":"Wang","year":"2021","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_82","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1016\/j.aca.2019.11.052","article-title":"Read-by-eye quantification of aluminum(III) in distance-based microfluidic paper-based analytical devices","volume":"1100","author":"Nguyen","year":"2020","journal-title":"Anal. Chim. Acta"},{"key":"ref_83","doi-asserted-by":"crossref","first-page":"361","DOI":"10.1016\/j.bios.2017.07.073","article-title":"A suspending-droplet mode paper-based microfluidic platform for low-cost, rapid, and convenient detection of lead(II) ions in liquid solution","volume":"99","author":"Sun","year":"2018","journal-title":"Biosens. Bioelectron."},{"key":"ref_84","doi-asserted-by":"crossref","first-page":"125112","DOI":"10.1016\/j.talanta.2023.125112","article-title":"A portable multi-channel fluorescent paper-based microfluidic chip based on smartphone imaging for simultaneous detection of four heavy metals","volume":"266","author":"Yuan","year":"2024","journal-title":"Talanta"},{"key":"ref_85","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1007\/s00604-023-05693-3","article-title":"Low-cost, portable, on-site fluorescent detection of As(III) by a paper-based microfluidic device based on aptamer and smartphone imaging","volume":"190","author":"Yuan","year":"2023","journal-title":"Microchim. Acta"},{"key":"ref_86","doi-asserted-by":"crossref","first-page":"111811","DOI":"10.1016\/j.foodcont.2025.111811","article-title":"Deep learning-enhanced microfluidic paper-based fluorescence sensor for simultaneous detection of pesticides and metal ions","volume":"182","author":"Yan","year":"2026","journal-title":"Food Control"},{"key":"ref_87","doi-asserted-by":"crossref","first-page":"2306","DOI":"10.1039\/D3LC01045G","article-title":"A novel ratiometric design of microfluidic paper-based analytical device for the simultaneous detection of Cu2+ and Fe3+ in drinking water using a fluorescent MOF@tetracycline nanocomposite","volume":"24","author":"Omer","year":"2024","journal-title":"Lab Chip"},{"key":"ref_88","doi-asserted-by":"crossref","first-page":"130591","DOI":"10.1016\/j.snb.2021.130567","article-title":"Acidified paper substrates for microfluidic solution sampling integrated with potentiometric sensors for determination of heavy metals","volume":"347","author":"Ding","year":"2021","journal-title":"Sens. Actuators B Chem."},{"key":"ref_89","doi-asserted-by":"crossref","first-page":"4500","DOI":"10.1039\/D2AN01108E","article-title":"Ion-selective membrane modified microfluidic paper-based solution sampling substrates for potentiometric heavy metal detection","volume":"147","author":"Silva","year":"2022","journal-title":"Analyst"},{"key":"ref_90","doi-asserted-by":"crossref","first-page":"933","DOI":"10.1016\/j.snb.2014.07.044","article-title":"Paper-based microfluidic sampling for potentiometric determination of ions","volume":"207","author":"Lisak","year":"2015","journal-title":"Sens. Actuators B Chem."},{"key":"ref_91","doi-asserted-by":"crossref","first-page":"347","DOI":"10.1016\/j.snb.2019.03.079","article-title":"Inorganic salt modified paper substrates utilized in paper based microfluidic sampling for potentiometric determination of heavy metals","volume":"290","author":"Ding","year":"2019","journal-title":"Sens. Actuators B Chem."},{"key":"ref_92","doi-asserted-by":"crossref","first-page":"339520","DOI":"10.1016\/j.aca.2022.339495","article-title":"Non-equilibrium potentiometric sensors integrated with metal modified paper-based microfluidic solution sampling substrates for determination of heavy metals in complex environmental samples","volume":"1197","author":"Silva","year":"2022","journal-title":"Anal. Chim. Acta"},{"key":"ref_93","doi-asserted-by":"crossref","first-page":"1702","DOI":"10.1039\/C6AY03414D","article-title":"A novel laminated polycaprolactone\/paper\/silver electrode for lead(II) detection","volume":"9","author":"Yu","year":"2017","journal-title":"Anal. Methods"},{"key":"ref_94","doi-asserted-by":"crossref","first-page":"4593","DOI":"10.1021\/acsomega.7b00611","article-title":"Modifier-free microfluidic electrochemical sensor for heavy-metal detection","volume":"2","author":"Shen","year":"2017","journal-title":"ACS Omega"},{"key":"ref_95","doi-asserted-by":"crossref","first-page":"223","DOI":"10.1016\/j.snb.2017.12.182","article-title":"Paper-based device with a sputtered tin-film electrode for the voltammetric determination of Cd(II) and Zn(II)","volume":"260","author":"Kokkinos","year":"2018","journal-title":"Sens. Actuators B Chem."},{"key":"ref_96","doi-asserted-by":"crossref","first-page":"342","DOI":"10.1007\/s12678-019-0512-8","article-title":"Printed paper-based electrochemical sensors for low-cost point-of-need applications","volume":"10","author":"Smith","year":"2019","journal-title":"Electrocatalysis"},{"key":"ref_97","doi-asserted-by":"crossref","first-page":"324","DOI":"10.1007\/s00604-018-2821-7","article-title":"Anodic stripping voltammetric determination of total arsenic using a gold nanoparticle-modified boron-doped diamond electrode on a paper-based device","volume":"185","author":"Pungjunun","year":"2018","journal-title":"Microchim. Acta"},{"key":"ref_98","doi-asserted-by":"crossref","first-page":"4100","DOI":"10.1021\/acs.analchem.6b05042","article-title":"Boron doped diamond paste electrodes for microfluidic paper-based analytical devices","volume":"89","author":"Nantaphol","year":"2017","journal-title":"Anal. Chem."},{"key":"ref_99","doi-asserted-by":"crossref","first-page":"113223","DOI":"10.1016\/j.microc.2025.113223","article-title":"Development of an origami paper-based electrochemical sensor using N-doped graphene for simultaneous detection of Cd(II), Pb(II), and Hg(II) in water","volume":"212","author":"Wei","year":"2025","journal-title":"Microchem. J."},{"key":"ref_100","doi-asserted-by":"crossref","first-page":"113310","DOI":"10.1016\/j.bios.2021.113310","article-title":"Electrochemical paper-based microfluidic device for on-line isolation of proteins and direct detection of lead in urine","volume":"187","author":"Wang","year":"2021","journal-title":"Biosens. Bioelectron."},{"key":"ref_101","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1039\/D3AY01787G","article-title":"Ion imprinted polymers integrated into a multi-functional microfluidic paper-based analytical device for trace cadmium detection in water","volume":"16","author":"Hu","year":"2024","journal-title":"Anal. Methods"},{"key":"ref_102","doi-asserted-by":"crossref","first-page":"1439","DOI":"10.1021\/acs.analchem.9b04632","article-title":"Janus electrochemical paper-based analytical devices for metals detection in aerosol samples","volume":"92","author":"Mettakoonpitak","year":"2020","journal-title":"Anal. Chem."},{"key":"ref_103","doi-asserted-by":"crossref","first-page":"123532","DOI":"10.1016\/j.talanta.2022.123548","article-title":"A fast, sensitive, low-cost electrochemical paper-based chip for real-time simultaneous detection of cadmium(II) and lead(II) via aptamer","volume":"247","author":"Qian","year":"2022","journal-title":"Talanta"},{"key":"ref_104","doi-asserted-by":"crossref","first-page":"111119","DOI":"10.1016\/j.microc.2024.111119","article-title":"An ultrasensitive, high throughput paper-based electrochemical chip for real-time detection of multiple heavy metal ions","volume":"204","author":"Yuan","year":"2024","journal-title":"Microchem. J."},{"key":"ref_105","doi-asserted-by":"crossref","first-page":"450","DOI":"10.1007\/s00604-022-05532-x","article-title":"A dual-readout paper-based analytical device for the simultaneous determination of hexavalent Cr and total Cr","volume":"189","author":"An","year":"2022","journal-title":"Microchim. Acta"},{"key":"ref_106","doi-asserted-by":"crossref","first-page":"540","DOI":"10.1016\/j.snb.2016.04.109","article-title":"High sensitivity and specificity simultaneous determination of lead, cadmium and copper using \u00b5PAD with dual electrochemical and colorimetric detection","volume":"233","author":"Chaiyo","year":"2016","journal-title":"Sens. Actuators B Chem."},{"key":"ref_107","doi-asserted-by":"crossref","first-page":"353","DOI":"10.14710\/jksa.26.9.353-362","article-title":"Development of microfluidic paper-based analytical devices (\u00b5PADs) for determination of Cd2+, Pb2+, and Cu2+ ions in mineral water","volume":"26","author":"Hermansyah","year":"2023","journal-title":"J. Kim. Sains Apl."},{"key":"ref_108","doi-asserted-by":"crossref","first-page":"3463","DOI":"10.1039\/D1AN00176K","article-title":"Plug-and-play assembly of paper-based colorimetric and electrochemical devices for multiplexed detection of metals","volume":"146","author":"Cardoso","year":"2021","journal-title":"Analyst"},{"key":"ref_109","doi-asserted-by":"crossref","first-page":"5414","DOI":"10.1039\/C6AY00954A","article-title":"A miniaturized chemiluminescence detection system for a microfluidic paper-based analytical device and its application to the determination of chromium(III)","volume":"8","author":"Alahmad","year":"2016","journal-title":"Anal. Methods"},{"key":"ref_110","doi-asserted-by":"crossref","first-page":"1941003","DOI":"10.1142\/S1793545819500160","article-title":"A flow chemiluminescence paper-based microfluidic device for detection of chromium(III) in water","volume":"12","author":"Shang","year":"2019","journal-title":"J. Innov. Opt. Health Sci."},{"key":"ref_111","doi-asserted-by":"crossref","first-page":"25884","DOI":"10.1021\/acs.jafc.5c08130","article-title":"Efficient heavy metals detection in plants: A microfluidic approach combined with laser-induced breakdown spectroscopy","volume":"73","author":"Yang","year":"2025","journal-title":"J. Agric. Food Chem."},{"key":"ref_112","doi-asserted-by":"crossref","first-page":"256","DOI":"10.1016\/j.bios.2016.04.061","article-title":"Detection of heavy metal by paper-based microfluidics","volume":"83","author":"Lin","year":"2016","journal-title":"Biosens. Bioelectron."},{"key":"ref_113","doi-asserted-by":"crossref","first-page":"1874","DOI":"10.1039\/C5AN02572A","article-title":"Paper-based analytical devices for environmental analysis","volume":"141","author":"Meredith","year":"2016","journal-title":"Analyst"},{"key":"ref_114","doi-asserted-by":"crossref","first-page":"196","DOI":"10.1016\/j.trac.2018.08.018","article-title":"Detection methods and applications of microfluidic paper-based analytical devices","volume":"107","author":"Fu","year":"2018","journal-title":"TrAC Trends Anal. Chem."},{"key":"ref_115","doi-asserted-by":"crossref","unstructured":"Mesquita, P., Gong, L., and Lin, Y. (2022). Low-cost microfluidics: Towards affordable environmental monitoring and assessment. Front. Lab Chip Technol., 1.","DOI":"10.3389\/frlct.2022.1074009"}],"container-title":["Micromachines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-666X\/17\/7\/780\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T04:17:36Z","timestamp":1783570656000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-666X\/17\/7\/780"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,26]]},"references-count":115,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["mi17070780"],"URL":"https:\/\/doi.org\/10.3390\/mi17070780","relation":{},"ISSN":["2072-666X"],"issn-type":[{"value":"2072-666X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,26]]}}}