{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,13]],"date-time":"2026-03-13T06:45:17Z","timestamp":1773384317251,"version":"3.50.1"},"reference-count":21,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2023,2,1]],"date-time":"2023-02-01T00:00:00Z","timestamp":1675209600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"FCT\/MCTES","doi-asserted-by":"publisher","award":["PTDC\/QUI-QIN\/28142\/2017"],"award-info":[{"award-number":["PTDC\/QUI-QIN\/28142\/2017"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"FCT\/MCTES","doi-asserted-by":"publisher","award":["NORTE-07-0162-FEDER-000048"],"award-info":[{"award-number":["NORTE-07-0162-FEDER-000048"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"FCT\/MCTES","doi-asserted-by":"publisher","award":["UIDB\/50016\/2020"],"award-info":[{"award-number":["UIDB\/50016\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"FCT\/MCTES","doi-asserted-by":"publisher","award":["UIDB\/50006\/2020"],"award-info":[{"award-number":["UIDB\/50006\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"FCT","doi-asserted-by":"publisher","award":["PTDC\/QUI-QIN\/28142\/2017"],"award-info":[{"award-number":["PTDC\/QUI-QIN\/28142\/2017"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"FCT","doi-asserted-by":"publisher","award":["NORTE-07-0162-FEDER-000048"],"award-info":[{"award-number":["NORTE-07-0162-FEDER-000048"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"FCT","doi-asserted-by":"publisher","award":["UIDB\/50016\/2020"],"award-info":[{"award-number":["UIDB\/50016\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"FCT","doi-asserted-by":"publisher","award":["UIDB\/50006\/2020"],"award-info":[{"award-number":["UIDB\/50006\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Chemosensors"],"abstract":"<jats:p>This work describes the development of an iron sensor based on a microfluidic paper-based technique, to attain iron quantification in natural waters. A new water-soluble naphthalene-3-hydroxy-4-pyridione ligand was used as a colour reagent, as it formed an orange complex with iron. As a newly described ligand, several chemical and physical parameters, namely, the sample and reagent volumes and reagent concentrations, were studied related to the formation of the coloured complex. The microfluidic paper-based analytical device (\u03bcPAD) assembly, namely, the use of different types of filter paper and different numbers of layers, was developed to obtain the best performance. Under the optimal conditions, a linear correlation was obtained in the range of 0.25\u20132.00 mg\/L of iron, with a minimum detectable value of 0.07 mg\/L. The proposed \u03bcPAD method was validated by an analysis of the certified samples and by a comparison of the tested water samples with the inductively coupled plasma (ICP) results (RE &lt; 10%). Then, the \u03bcPAD device was successfully applied to the determination of iron in tap water, well water, river water, and seawater, with no need for any prior sample pre-treatment; recovery studies were also performed (average = 100.3% with RSD = 4.2%).<\/jats:p>","DOI":"10.3390\/chemosensors11020101","type":"journal-article","created":{"date-parts":[[2023,2,1]],"date-time":"2023-02-01T05:04:48Z","timestamp":1675227888000},"page":"101","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Iron Determination in Natural Waters Using a Synthesised 3-Hydroxy-4-Pyridione Ligand in a Newly Developed Microfluidic Paper-Based Device"],"prefix":"10.3390","volume":"11","author":[{"given":"Juliana I. S.","family":"Aguiar","sequence":"first","affiliation":[{"name":"CBQF\u2014Centro de Biotecnologia e Qu\u00edmica Fina, Laborat\u00f3rio Associado, Escola Superior de Biotecnologia, Universidade Cat\u00f3lica Portuguesa, 4169-005 Porto, Portugal"}]},{"given":"Susana O.","family":"Ribeiro","sequence":"additional","affiliation":[{"name":"REQUIMTE-LAQV, Departamento de Qu\u00edmica e Bioqu\u00edmica, Faculdade de Ci\u00eancias, Universidade do Porto, 4169-007 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1967-8853","authenticated-orcid":false,"given":"Andreia","family":"Leite","sequence":"additional","affiliation":[{"name":"REQUIMTE-LAQV, Departamento de Qu\u00edmica e Bioqu\u00edmica, Faculdade de Ci\u00eancias, Universidade do Porto, 4169-007 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0998-1437","authenticated-orcid":false,"given":"Maria","family":"Rangel","sequence":"additional","affiliation":[{"name":"REQUIMTE-LAQV, Instituto de Ci\u00eancias Biom\u00e9dicas de Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal"}]},{"given":"Ant\u00f3nio O. S. S.","family":"Rangel","sequence":"additional","affiliation":[{"name":"CBQF\u2014Centro de Biotecnologia e Qu\u00edmica Fina, Laborat\u00f3rio Associado, Escola Superior de Biotecnologia, Universidade Cat\u00f3lica Portuguesa, 4169-005 Porto, Portugal"}]},{"given":"Raquel B. R.","family":"Mesquita","sequence":"additional","affiliation":[{"name":"CBQF\u2014Centro de Biotecnologia e Qu\u00edmica Fina, Laborat\u00f3rio Associado, Escola Superior de Biotecnologia, Universidade Cat\u00f3lica Portuguesa, 4169-005 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2023,2,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"120887","DOI":"10.1016\/j.talanta.2020.120887","article-title":"Use of an Ether-Derived 3-Hydroxy-4-Pyridinone Chelator as a New Chromogenic Reagent in the Development of a Microfluidic Paper-Based Analytical Device for Fe(III) Determination in Natural Waters","volume":"214","author":"Moniz","year":"2020","journal-title":"Talanta"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"169","DOI":"10.2116\/analsci.22.169","article-title":"Sequential Determination of Trace Amounts of Iron and Copper in Water Samples by Flow Injection Analysis with Catalytic Spectrophotometric Detection","volume":"22","author":"Lunvongsa","year":"2006","journal-title":"Anal. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"532","DOI":"10.1016\/j.saa.2015.07.017","article-title":"Miniaturization of Spectrophotometry Based on Micro Flow Analysis Using Norfloxacin as Less-Toxic Reagent for Iron Determination","volume":"151","author":"Prasertboonyai","year":"2015","journal-title":"Spectrochim. Acta A Mol. Biomol. Spectrosc."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"703","DOI":"10.1016\/j.talanta.2017.02.055","article-title":"Microsequential Injection Lab-on-Valve System for the Spectrophotometric Bi-Parametric Determination of Iron and Copper in Natural Waters","volume":"167","author":"Mesquita","year":"2017","journal-title":"Talanta"},{"key":"ref_5","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_6","doi-asserted-by":"crossref","first-page":"121183","DOI":"10.1016\/j.talanta.2020.121183","article-title":"Novel Microfluidic Paper-Based Analytical Devices (\u039cPADs) for the Determination of Nitrate and Nitrite in Human Saliva","volume":"219","author":"Ferreira","year":"2020","journal-title":"Talanta"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1016\/j.aca.2016.03.030","article-title":"Development of a Microfluidic Paper-Based Analytical Device for the Determination of Salivary Aldehydes","volume":"919","author":"Ramdzan","year":"2016","journal-title":"Anal. Chim. Acta"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Lace, A., and Cleary, J. (2021). A Review of Microfluidic Detection Strategies for Heavy Metals in Water. Chemosensors, 9.","DOI":"10.3390\/chemosensors9040060"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1021\/ac9013989","article-title":"Diagnostics for the Developing World Microfluidic.Pdf","volume":"82","author":"Martinez","year":"2010","journal-title":"Anal. Chem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1318","DOI":"10.1002\/anie.200603817","article-title":"Patterned Paper as a Platform for Inexpensive, Low-Volume, Portable Bioassays","volume":"46","author":"Martinez","year":"2007","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"407","DOI":"10.1080\/00450618.2020.1740321","article-title":"A Portable Microfluidic Paper-Based Analytical Device for Blood Detection and Typing Assay","volume":"53","author":"Ansari","year":"2021","journal-title":"Aust. J. Forensic Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"176","DOI":"10.1016\/j.talanta.2017.08.072","article-title":"Developments of Microfluidic Paper-Based Analytical Devices (\u039cPADs) for Water Analysis: A Review","volume":"177","author":"Almeida","year":"2018","journal-title":"Talanta"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"7463","DOI":"10.1007\/s00216-021-03706-9","article-title":"New Microfluidic Paper-Based Analytical Device for Iron Determination in Urine Samples","volume":"413","author":"Ferreira","year":"2021","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"3085","DOI":"10.1039\/C8AN00632F","article-title":"Quantitative Colorimetric Paper Analytical Devices Based on Radial Distance Measurements for Aqueous Metal Determination","volume":"143","author":"Hofstetter","year":"2018","journal-title":"Analyst"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1773","DOI":"10.1007\/s10895-016-1869-1","article-title":"Design of a Water Soluble Fluorescent 3-Hydroxy-4-Pyridinone Ligand Active at Physiological PH Values","volume":"26","author":"Leite","year":"2016","journal-title":"J. Fluoresc."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1016\/j.poly.2018.12.005","article-title":"New Hydrophilic 3-Hydroxy-4-Pyridinone Chelators with Ether-Derived Substituents: Synthesis and Evaluation of Analytical Performance in the Determination of Iron in Waters","volume":"160","author":"Moniz","year":"2019","journal-title":"Polyhedron"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/j.talanta.2014.03.059","article-title":"Iron Speciation by Microsequential Injection Solid Phase Spectrometry Using 3-Hydroxy-1(H)-2-Methyl-4-Pyridinone as Chromogenic Reagent","volume":"133","author":"Mesquita","year":"2015","journal-title":"Talanta"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"633","DOI":"10.1016\/j.talanta.2015.05.062","article-title":"Iron Speciation in Natural Waters by Sequential Injection Analysis with a Hexadentate 3-Hydroxy-4-Pyridinone Chelator as Chromogenic Agent","volume":"148","author":"Miranda","year":"2016","journal-title":"Talanta"},{"key":"ref_19","unstructured":"(1998). Standard Methods for the Examination of Water and Wastewater, American Public Health Association. [19th ed.]."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2201","DOI":"10.1351\/pac200274112201","article-title":"Use of the Terms \u201cRecovery\u201d and \u201cApparent Recovery\u201d in Analytical Procedures (IUPAC Recommendations 2002)","volume":"74","author":"Burns","year":"2003","journal-title":"Pure Appl. Chem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1699","DOI":"10.1351\/pac199567101699","article-title":"Nomenclature in Evaluation of Analytical Methods Including Detection and Quantification Capabilities (IUPAC Recommendations 1995)","volume":"67","author":"Currie","year":"1995","journal-title":"Pure Appl. Chem."}],"container-title":["Chemosensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2227-9040\/11\/2\/101\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T18:20:55Z","timestamp":1760120455000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2227-9040\/11\/2\/101"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,2,1]]},"references-count":21,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2023,2]]}},"alternative-id":["chemosensors11020101"],"URL":"https:\/\/doi.org\/10.3390\/chemosensors11020101","relation":{},"ISSN":["2227-9040"],"issn-type":[{"value":"2227-9040","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,2,1]]}}}