{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,13]],"date-time":"2025-11-13T12:42:18Z","timestamp":1763037738622,"version":"build-2065373602"},"reference-count":27,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2022,5,29]],"date-time":"2022-05-29T00:00:00Z","timestamp":1653782400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"ULVAC Inc.","award":["IH150100028"],"award-info":[{"award-number":["IH150100028"]}]},{"DOI":"10.13039\/501100000923","name":"Australian Research Council Integrated Devices for End-User Analysis at Low Levels Research (IDEAL)","doi-asserted-by":"publisher","award":["IH150100028"],"award-info":[{"award-number":["IH150100028"]}],"id":[{"id":"10.13039\/501100000923","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Australian Academy of Science on behalf of the Department of Industry, Innovation and Science","award":["IH150100028"],"award-info":[{"award-number":["IH150100028"]}]},{"name":"Australian Government under the National Innovation and Science Agend","award":["IH150100028"],"award-info":[{"award-number":["IH150100028"]}]},{"name":"Australia\u2019s National Collaborative Research Infrastructure Strategy (NCRIS)","award":["IH150100028"],"award-info":[{"award-number":["IH150100028"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The rapid development of optofluidic technologies in recent years has seen the need for sensing platforms with ease-of-use, simple sample manipulation, and high performance and sensitivity. Herein, an integrated optofluidic sensor consisting of a pillar array-based open microfluidic chip and caged dye-doped whispering gallery mode microspheres is demonstrated and shown to have potential for simple real-time monitoring of liquids. The open microfluidic chip allows for the wicking of a thin film of liquid across an open surface with subsequent evaporation-driven flow enabling continuous passive flow for sampling. The active dye-doped whispering gallery mode microspheres placed between pillars, avoid the use of cumbersome fibre tapers to couple light to the resonators as is required for passive microspheres. The performance of this integrated sensor is demonstrated using glucose solutions (0.05\u20130.3 g\/mL) and the sensor response is shown to be dynamic and reversible. The sensor achieves a refractive index sensitivity of ~40 nm\/RIU, with Q-factors of ~5 \u00d7 103 indicating a detection limit of ~3 \u00d7 10\u22123 RIU (~20 mg\/mL glucose). Further enhancement of the detection limit is expected by increasing the microsphere Q-factor using high-index materials for the resonators, or alternatively, inducing lasing. The integrated sensors are expected to have significant potential for a host of downstream applications, particularly relating to point-of-care diagnostics.<\/jats:p>","DOI":"10.3390\/s22114135","type":"journal-article","created":{"date-parts":[[2022,5,31]],"date-time":"2022-05-31T02:30:06Z","timestamp":1653964206000},"page":"4135","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Caged-Sphere Optofluidic Sensors: Whispering Gallery Resonators in Wicking Microfluidics"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6803-0666","authenticated-orcid":false,"given":"Nicolas","family":"Riesen","sequence":"first","affiliation":[{"name":"Future Industries Institute, STEM, University of South Australia, Mawson Lakes, SA 5095, Australia"},{"name":"ARC Research Hub for Integrated Devices for End-User Analysis at Low-Levels (IDEAL), Future Industries Institute, STEM, University of South Australia, Mawson Lakes, SA 5095, Australia"},{"name":"Institute for Photonics and Advanced Sensing, University of Adelaide, Adelaide, SA 5005, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zane Q.","family":"Peterkovic","sequence":"additional","affiliation":[{"name":"Future Industries Institute, STEM, University of South Australia, Mawson Lakes, SA 5095, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1247-6914","authenticated-orcid":false,"given":"Bin","family":"Guan","sequence":"additional","affiliation":[{"name":"Future Industries Institute, STEM, University of South Australia, Mawson Lakes, SA 5095, Australia"},{"name":"ARC Research Hub for Integrated Devices for End-User Analysis at Low-Levels (IDEAL), Future Industries Institute, STEM, University of South Australia, Mawson Lakes, SA 5095, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alexandre","family":"Fran\u00e7ois","sequence":"additional","affiliation":[{"name":"Future Industries Institute, STEM, University of South Australia, Mawson Lakes, SA 5095, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"David G.","family":"Lancaster","sequence":"additional","affiliation":[{"name":"Future Industries Institute, STEM, University of South Australia, Mawson Lakes, SA 5095, Australia"},{"name":"ARC Research Hub for Integrated Devices for End-User Analysis at Low-Levels (IDEAL), Future Industries Institute, STEM, University of South Australia, Mawson Lakes, SA 5095, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8861-2161","authenticated-orcid":false,"given":"Craig","family":"Priest","sequence":"additional","affiliation":[{"name":"Future Industries Institute, STEM, University of South Australia, Mawson Lakes, SA 5095, Australia"},{"name":"ARC Research Hub for Integrated Devices for End-User Analysis at Low-Levels (IDEAL), Future Industries Institute, STEM, University of South Australia, Mawson Lakes, SA 5095, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,5,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"591","DOI":"10.1038\/nphoton.2011.206","article-title":"Optofluidic microsystems for chemical and biological analysis","volume":"5","author":"Fan","year":"2011","journal-title":"Nat. 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