{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,31]],"date-time":"2025-12-31T14:52:30Z","timestamp":1767192750517,"version":"build-2065373602"},"reference-count":57,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2020,9,19]],"date-time":"2020-09-19T00:00:00Z","timestamp":1600473600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003500","name":"Universit\u00e0 degli Studi di Padova","doi-asserted-by":"publisher","award":["BIRD165523\/16","STARS2020"],"award-info":[{"award-number":["BIRD165523\/16","STARS2020"]}],"id":[{"id":"10.13039\/501100003500","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The aim of Lab-on-a-chip systems is the downscaling of analytical protocols into microfluidic devices, including optical measurements. In this context, the growing interest of the scientific community in opto-microfluidic devices has fueled the development of new materials. Recently, lithium niobate has been presented as a promising material for this scope, thanks to its remarkable optical and physicochemical properties. Here, we present a novel microfluidic device realized starting from a lithium niobate crystal, combining engraved microfluidic channels with integrated and self-aligned optical waveguides. Notably, the proposed microfabrication strategy does not compromise the optical coupling between the waveguides and the microchannel, allowing one to measure the transmitted light through the liquid flowing in the channel. In addition, the device shows a high versatility in terms of the optical properties of the light source, such as wavelength and polarization. Finally, the developed opto-microfluidic system is successfully validated as a probe for real-time pH monitoring of the liquid flowing inside the microchannel, showing a high integrability and fast response.<\/jats:p>","DOI":"10.3390\/s20185366","type":"journal-article","created":{"date-parts":[[2020,9,19]],"date-time":"2020-09-19T07:06:09Z","timestamp":1600499169000},"page":"5366","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Opto-Microfluidic System for Absorbance Measurements in Lithium Niobate Device Applied to pH Measurements"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8087-7539","authenticated-orcid":false,"given":"Riccardo","family":"Zamboni","sequence":"first","affiliation":[{"name":"Physics and Astronomy Department G. Galileo, University of Padova, Via Marzolo 8, 35121 Padova, Italy"}]},{"given":"Annamaria","family":"Zaltron","sequence":"additional","affiliation":[{"name":"Physics and Astronomy Department G. Galileo, University of Padova, Via Marzolo 8, 35121 Padova, Italy"}]},{"given":"Elena","family":"Izzo","sequence":"additional","affiliation":[{"name":"Physics and Astronomy Department G. Galileo, University of Padova, Via Marzolo 8, 35121 Padova, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6196-8638","authenticated-orcid":false,"given":"Gregorio","family":"Bottaro","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Institute of Condensed Matter Chemistry and Technologies for Energy (ICMATE), National Research Council (CNR), University of Padova, via Marzolo 1, 35131 Padova, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6760-7988","authenticated-orcid":false,"given":"Davide","family":"Ferraro","sequence":"additional","affiliation":[{"name":"Physics and Astronomy Department G. Galileo, University of Padova, Via Marzolo 8, 35121 Padova, Italy"}]},{"given":"Cinzia","family":"Sada","sequence":"additional","affiliation":[{"name":"Physics and Astronomy Department G. Galileo, University of Padova, Via Marzolo 8, 35121 Padova, Italy"}]}],"member":"1968","published-online":{"date-parts":[[2020,9,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"368","DOI":"10.1038\/nature05058","article-title":"The origins and the future of microfluidics","volume":"442","author":"Whitesides","year":"2006","journal-title":"Nature"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1094","DOI":"10.1039\/b706364b","article-title":"Microfluidic platforms for lab-on-a-chip applications","volume":"7","author":"Haeberle","year":"2007","journal-title":"Lab Chip"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Mark, D., Haeberle, S., Roth, G., Von Stetten, F., and Zengerle, R. (2010). Microfluidic Lab-on-a-Chip Platforms. 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