{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T03:19:08Z","timestamp":1760239148734,"version":"build-2065373602"},"reference-count":36,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2020,9,23]],"date-time":"2020-09-23T00:00:00Z","timestamp":1600819200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Ministry of Science and Technology","award":["107-2221-E-006-054-MY3"],"award-info":[{"award-number":["107-2221-E-006-054-MY3"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biosensors"],"abstract":"<jats:p>Handy and disposable point-of-care diagnostics facilitate the early screening of severe diseases in resource-limited areas. To address urgent needs in inconvenient sites, a simple colorimetric diagnostic device equipped with a capillary tube with porous hydrogel and immunocomplex particles was developed for the rapid detection of biomarkers (16 min). In this device, probe particles attach to capture particles (dp = 40 \u00b5m) and form sandwiched immunocomplexes in the presence of target biomarkers, and a red color progressively emerges when the sandwiched immunocomplex particles are blocked by the porous hydrogel embedded inside the glass capillary. Colorimetric aggregation was recorded using a smartphone and analyzed with imaging software. The limit of detection reached 1 ng\/mL and showed a maximum of 79% accuracy compared with that obtained through a conventional spectrophotometric technique. The level of a diabetic retinopathy (DR) biomarker, lipocalin-1 (LCN-1), was measured in 1 \u00b5L of a human tear sample and used in testing the practicability of the proposed device. All healthy subjects showed lower intensity levels than the other diabetic counterparts (proliferative DR or nonproliferative DR patients), implying the potential of this device in clinical applications. Overall, the diagnostic device facilitates point-of-care-testing and provides a low-cost (~1 USD), compact, and reliable tool for early diagnosis in resource-limited areas.<\/jats:p>","DOI":"10.3390\/bios10100130","type":"journal-article","created":{"date-parts":[[2020,9,23]],"date-time":"2020-09-23T09:28:08Z","timestamp":1600853288000},"page":"130","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Colorimetric Diagnostic Capillary Enabled by Size Sieving in a Porous Hydrogel"],"prefix":"10.3390","volume":"10","author":[{"given":"John Mello Camille C.","family":"Guzman","sequence":"first","affiliation":[{"name":"Department of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4029-4125","authenticated-orcid":false,"given":"Sheng-Min","family":"Hsu","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, National Cheng Kung University Hospital, Tainan 701, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7257-6565","authenticated-orcid":false,"given":"Han-Sheng","family":"Chuang","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan"},{"name":"Center for Micro\/Nano Science and Technology, National Cheng Kung University, Tainan 701, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,9,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"101214","DOI":"10.1016\/j.ctcp.2020.101214","article-title":"A narrative literature review on traditional medicine options for treatment of corona virus disease 2019 (COVID-19)","volume":"40","author":"Mirzaie","year":"2020","journal-title":"Complement. Ther. Clin. Pract."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"126","DOI":"10.1007\/s11684-020-0767-8","article-title":"Coronavirus disease 2019 (COVID-19): A clinical update","volume":"14","author":"Zhou","year":"2020","journal-title":"Front. Med."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"112437","DOI":"10.1016\/j.bios.2020.112437","article-title":"Multiplex reverse transcription loop-mediated isothermal amplification combined with nanoparticle-based lateral flow biosensor for the diagnosis of COVID-19","volume":"166","author":"Zhu","year":"2020","journal-title":"Biosens. Bioelectron."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1016\/j.bios.2017.10.002","article-title":"Enhanced diffusometric immunosensing with grafted gold nanoparticles for detection of diabetic retinopathy biomarker tumor necrosis factor-\u03b1","volume":"101","author":"Chuang","year":"2018","journal-title":"Biosens. Bioelectron."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.snb.2015.10.053","article-title":"Micro-magnetofluidics in microfluidic systems: A review","volume":"224","author":"Yang","year":"2016","journal-title":"Sens. Actuators B Chem."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"3623","DOI":"10.1016\/j.snb.2017.09.080","article-title":"Rapid microfluidic paper-based platform for low concentration formaldehyde detection","volume":"255","author":"Guzman","year":"2018","journal-title":"Sens. Actuators B Chem."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1800663","DOI":"10.1002\/admt.201800663","article-title":"Advances of Microfluidics in Biomedical Engineering","volume":"4","author":"Zhong","year":"2019","journal-title":"Adv. Mater. Technol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"30011","DOI":"10.3390\/s151229783","article-title":"Microfluidics Integrated Biosensors: A Leading Technology towards Lab-on-a-Chip and Sensing Applications","volume":"15","author":"Luka","year":"2015","journal-title":"Sensors"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1016\/j.sbsr.2014.10.010","article-title":"Amorphous silicon photosensors integrated in microfluidic structures as a technological demonstrator of a \u201ctrue\u201d Lab-on-Chip system","volume":"3","author":"Caputo","year":"2015","journal-title":"Sens. Bio-Sens. Res."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"479","DOI":"10.1007\/s10404-012-1066-8","article-title":"Rapid prototyping of glass-based microfluidic chips utilizing two-pass defocused CO2 laser beam method","volume":"14","author":"Fu","year":"2012","journal-title":"Microfluid. Nanofluidics"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1016\/j.aca.2012.10.022","article-title":"Separation of carboxylic acids in human serum by isotachophoresis using a commercial field-deployable analytical platform combined with in-house glass microfluidic chips","volume":"755","author":"Smejkal","year":"2012","journal-title":"Anal. Chim. Acta"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"380","DOI":"10.1016\/j.bios.2015.04.080","article-title":"A microfluidic chip integrated with a high-density PDMS-based microfiltration membrane for rapid isolation and detection of circulating tumor cells","volume":"71","author":"Fan","year":"2015","journal-title":"Biosens. Bioelectron."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/j.snb.2016.01.120","article-title":"Uniform droplet splitting and detection using Lab-on-Chip flow cytometry on a microfluidic PDMS device","volume":"229","author":"Hanczyc","year":"2016","journal-title":"Sens. Actuators B Chem."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1951","DOI":"10.3233\/BME-141004","article-title":"Fabrication of multilayer-PDMS based microfluidic device for bio-particles concentration detection","volume":"24","author":"Masrie","year":"2014","journal-title":"Bio-Med. Mater. Eng."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"114","DOI":"10.1016\/j.supflu.2015.08.019","article-title":"Sterilization of PMMA microfluidic chips by various techniques and investigation of material characteristics","volume":"107","author":"Yavuz","year":"2016","journal-title":"J. Supercrit. Fluids"},{"key":"ref_16","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_17","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1016\/j.talanta.2015.04.068","article-title":"Low-cost bioanalysis on paper-based and its hybrid microfluidic platforms","volume":"145","author":"Dou","year":"2015","journal-title":"Talanta"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"390","DOI":"10.1016\/j.talanta.2015.10.013","article-title":"Paper-based analytical device for instrumental-free detection of thiocyanate in saliva as a biomarker of tobacco smoke exposure","volume":"147","author":"Lavilla","year":"2016","journal-title":"Talanta"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"774","DOI":"10.1016\/j.bios.2015.10.032","article-title":"Fabrication techniques for microfluidic paper-based analytical devices and their applications for biological testing: A review","volume":"77","author":"Xia","year":"2016","journal-title":"Biosens. Bioelectron."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1021\/ac9013989","article-title":"Diagnostics for the Developing World: Microfluidic Paper-Based Analytical Devices","volume":"82","author":"Martinez","year":"2010","journal-title":"Anal. Chem."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Singh, A.T., Lantigua, D., Meka, A., Taing, S., Pandher, M., and Camci-Unal, G. (2018). Paper-Based Sensors: Emerging Themes and Applications. Sensors, 18.","DOI":"10.3390\/s18092838"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"887","DOI":"10.1016\/j.trac.2011.01.019","article-title":"Point-of-care testing (POCT): Current techniques and future perspectives","volume":"30","author":"Luppa","year":"2011","journal-title":"TrAC Trends Anal. Chem."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"132","DOI":"10.1016\/j.tibtech.2014.01.003","article-title":"Point-of-care technologies for molecular diagnostics using a drop of blood","volume":"32","author":"Song","year":"2014","journal-title":"Trends Biotechnol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"487","DOI":"10.1021\/ac2030199","article-title":"Point of Care Diagnostics: Status and Future","volume":"84","author":"Gubala","year":"2012","journal-title":"Anal. Chem."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"692","DOI":"10.1016\/j.tibtech.2015.09.001","article-title":"Emerging Technologies for Next-Generation Point-of-Care Testing","volume":"33","author":"Vashist","year":"2015","journal-title":"Trends Biotechnol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"138","DOI":"10.1016\/j.cca.2019.03.008","article-title":"Point of care testing for infectious diseases","volume":"493","author":"Chen","year":"2019","journal-title":"Clin. Chim. Acta"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"96","DOI":"10.1016\/j.talanta.2019.04.054","article-title":"Detection platforms for point-of-care testing based on colorimetric, luminescent and magnetic assays: A review","volume":"202","author":"Yang","year":"2019","journal-title":"Talanta"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1015","DOI":"10.1038\/nm.2408","article-title":"Microfluidics-based diagnostics of infectious diseases in the developing world","volume":"17","author":"Chin","year":"2011","journal-title":"Nat. Med."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"356","DOI":"10.1039\/C9LC00975B","article-title":"Sensitive tear screening of diabetic retinopathy with dual biomarkers enabled using a rapid electrokinetic patterning platform","volume":"20","author":"Wang","year":"2020","journal-title":"Lab Chip"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"438","DOI":"10.1016\/j.biotechadv.2013.01.006","article-title":"Point-of-care assays for tuberculosis: Role of nanotechnology\/microfluidics","volume":"31","author":"Wang","year":"2013","journal-title":"Biotechnol. Adv."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"120211","DOI":"10.1016\/j.talanta.2019.120211","article-title":"A feasible image-based colorimetric assay using a smartphone RGB camera for point-of-care monitoring of diabetes","volume":"206","author":"Wang","year":"2020","journal-title":"Talanta"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"3232","DOI":"10.1039\/c3lc50431j","article-title":"Smartphone based health accessory for colorimetric detection of biomarkers in sweat and saliva","volume":"13","author":"Oncescu","year":"2013","journal-title":"Lab Chip"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1016\/j.cis.2017.10.007","article-title":"Surface self-assembly of colloidal crystals for micro- and nano-patterning","volume":"251","author":"Fanzio","year":"2018","journal-title":"Adv. Colloid Interface Sci."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"11347","DOI":"10.1021\/la202088s","article-title":"Fast Evaporation of Spreading Droplets of Colloidal Suspensions","volume":"27","author":"Maki","year":"2011","journal-title":"Langmuir"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"319","DOI":"10.1007\/s13404-013-0122-9","article-title":"Demonstrative experiments about gold nanoparticles and nanofilms: An introduction to nanoscience","volume":"46","author":"Pluchery","year":"2013","journal-title":"Gold Bull."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"2196","DOI":"10.1016\/j.jprot.2012.01.019","article-title":"Quantitative analysis of proteins in the tear fluid of patients with diabetic retinopathy","volume":"75","author":"Csosz","year":"2012","journal-title":"J. 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