{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,16]],"date-time":"2026-01-16T02:56:58Z","timestamp":1768532218965,"version":"3.49.0"},"reference-count":38,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2021,8,12]],"date-time":"2021-08-12T00:00:00Z","timestamp":1628726400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002803","name":"Fondazione Cariplo","doi-asserted-by":"publisher","award":["Project AGER2 - Rif. 2016-0169"],"award-info":[{"award-number":["Project AGER2 - Rif. 2016-0169"]}],"id":[{"id":"10.13039\/501100002803","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In recent years, there has been a continuously growing interest in antioxidants by both customers and food industry. The beneficial health effects of antioxidants led to their widespread use in fortified functional foods, as dietary supplements and as preservatives. A variety of analytical methods are available to evaluate the total antioxidant capacity (TAC) of food extracts and beverages. However, most of them are expensive, time-consuming, and require laboratory instrumentation. Therefore, simple, cheap, and fast portable sensors for point-of-need measurement of antioxidants in food samples are needed. Here, we describe a smartphone-based chemosensor for on-site assessment of TAC of aqueous matrices, relying on the antioxidant-induced formation of gold nanoparticles. The reaction takes place in ready-to-use analytical cartridges containing an hydrogel reaction medium preloaded with Au(III) and is monitored by using the smartphone\u2019s CMOS camera. An analytical device including an LED-based lighting system was developed to ensure uniform and reproducible illumination of the analytical cartridge. The chemosensor permitted rapid TAC measurements of aqueous samples, including teas, herbal infusions, beverages, and extra virgin olive oil extracts, providing results that correlated with those of the reference methods for TAC assessment, e.g., oxygen radical absorbance capacity (ORAC).<\/jats:p>","DOI":"10.3390\/s21165432","type":"journal-article","created":{"date-parts":[[2021,8,12]],"date-time":"2021-08-12T10:54:41Z","timestamp":1628765681000},"page":"5432","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":23,"title":["A Smartphone-Based Chemosensor to Evaluate Antioxidants in Agri-Food Matrices by In Situ AuNP Formation"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8215-9458","authenticated-orcid":false,"given":"Donato","family":"Calabria","sequence":"first","affiliation":[{"name":"Department of Chemistry \u201cGiacomo Ciamician\u201d, Alma Mater Studiorum-University of Bologna, Via Francesco Selmi 2, I-40126 Bologna, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Massimo","family":"Guardigli","sequence":"additional","affiliation":[{"name":"Department of Chemistry \u201cGiacomo Ciamician\u201d, Alma Mater Studiorum-University of Bologna, Via Francesco Selmi 2, I-40126 Bologna, Italy"},{"name":"Interdepartmental Centre for Industrial Research in Renewable Resources, Environment, Sea and Energy (CIRI FRAME), Alma Mater Studiorum-University of Bologna, Via Sant\u2019Alberto 163, I-48123 Ravenna, Italy"},{"name":"Interdepartmental Centre for Industrial Aerospace Research (CIRI Aerospace), Alma Mater Studiorum-University of Bologna, Via Baldassarre Canaccini 12, I-47121 Forl\u00ec, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Paolo","family":"Severi","sequence":"additional","affiliation":[{"name":"Department of Chemistry \u201cGiacomo Ciamician\u201d, Alma Mater Studiorum-University of Bologna, Via Francesco Selmi 2, I-40126 Bologna, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ilaria","family":"Trozzi","sequence":"additional","affiliation":[{"name":"Department of Chemistry \u201cGiacomo Ciamician\u201d, Alma Mater Studiorum-University of Bologna, Via Francesco Selmi 2, I-40126 Bologna, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andrea","family":"Pace","sequence":"additional","affiliation":[{"name":"Department of Chemistry \u201cGiacomo Ciamician\u201d, Alma Mater Studiorum-University of Bologna, Via Francesco Selmi 2, I-40126 Bologna, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Stefano","family":"Cinti","sequence":"additional","affiliation":[{"name":"Department of Pharmacy, University Naples Federico II, Via Domenico Montesano 49, I-80131 Naples, Italy"},{"name":"BAT Center\u2212Interuniversity Center for Studies on Bioinspired Agro-Environmental Technology, University of Napoli \u201cFederico II\u201d, I-80055 Portici, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Martina","family":"Zangheri","sequence":"additional","affiliation":[{"name":"Department of Chemistry \u201cGiacomo Ciamician\u201d, Alma Mater Studiorum-University of Bologna, Via Francesco Selmi 2, I-40126 Bologna, Italy"},{"name":"Interdepartmental Centre for Industrial Agrofood Research (CIRI Agrofood), Alma Mater Studiorum-University of Bologna, Via Quinto Bucci 336, I-47521 Cesena, Italy"},{"name":"Interdepartmental Centre for Industrial Research in Advanced Mechanical Engineering Applications and Materials Technology (CIRI MAM), Alma Mater Studiorum-University of Bologna, Viale Risorgimento 2, I-40136 Bologna, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6553-5039","authenticated-orcid":false,"given":"Mara","family":"Mirasoli","sequence":"additional","affiliation":[{"name":"Department of Chemistry \u201cGiacomo Ciamician\u201d, Alma Mater Studiorum-University of Bologna, Via Francesco Selmi 2, I-40126 Bologna, Italy"},{"name":"Interdepartmental Centre for Industrial Research in Renewable Resources, Environment, Sea and Energy (CIRI FRAME), Alma Mater Studiorum-University of Bologna, Via Sant\u2019Alberto 163, I-48123 Ravenna, Italy"},{"name":"Interdepartmental Centre for Industrial Aerospace Research (CIRI Aerospace), Alma Mater Studiorum-University of Bologna, Via Baldassarre Canaccini 12, I-47121 Forl\u00ec, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,8,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"129499","DOI":"10.1016\/j.chemosphere.2020.129499","article-title":"A review of dietary phytochemicals and their relation to oxidative stress and human 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