{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,16]],"date-time":"2025-10-16T20:38:53Z","timestamp":1760647133346,"version":"build-2065373602"},"reference-count":54,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2019,12,29]],"date-time":"2019-12-29T00:00:00Z","timestamp":1577577600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Allantoin, the natural end product of purine catabolism in mammals, is non-enzymatically produced from the scavenging of reactive oxygen species through the degradation of uric acid. Levels of allantoin in biological fluids are sensitively influenced by the presence of free radicals, making this molecule a candidate marker of acute oxidative stress in clinical analyses. With this aim, we exploited allantoinase\u2014the enzyme responsible for allantoin hydrolization in plants and lower organisms\u2014for the development of a biosensor exploiting a fast enzymatic-chemical assay for allantoin quantification. Recombinant allantoinase was entrapped in a wet nanoporous silica gel matrix and its structural properties, function, and stability were characterized through fluorescence spectroscopy and circular dichroism measurements, and compared to the soluble enzyme. Physical immobilization in silica gel minimally influences the structure and the catalytic efficiency of entrapped allantoinase, which can be reused several times and stored for several months with good activity retention. These results, together with the relative ease of the sol-gel preparation and handling, make the encapsulated allantoinase a good candidate for the development of an allantoin biosensor.<\/jats:p>","DOI":"10.3390\/s20010196","type":"journal-article","created":{"date-parts":[[2019,12,30]],"date-time":"2019-12-30T05:49:41Z","timestamp":1577684981000},"page":"196","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Immobilization of Allantoinase for the Development of an Optical Biosensor of Oxidative Stress States"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4615-6786","authenticated-orcid":false,"given":"Marialaura","family":"Marchetti","sequence":"first","affiliation":[{"name":"Centro Interdipartimentale Biopharmanet-TEC, Universit\u00e0 di Parma, Parco Area delle Scienze 27\/A, 43124 Parma, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5389-2669","authenticated-orcid":false,"given":"Luca","family":"Ronda","sequence":"additional","affiliation":[{"name":"Centro Interdipartimentale Biopharmanet-TEC, Universit\u00e0 di Parma, Parco Area delle Scienze 27\/A, 43124 Parma, Italy"},{"name":"Dipartimento di Medicina e Chirurgia, Universit\u00e0 di Parma, Via Gramsci 14, 43126 Parma, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Riccardo","family":"Percudani","sequence":"additional","affiliation":[{"name":"Dipartimento di Scienze Chimiche, della Vita e della Sostenibilit\u00e0 Ambientale, Universit\u00e0 di Parma, Via Parco Area delle Scienze 11\/A, 43124 Parma, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6787-0594","authenticated-orcid":false,"given":"Stefano","family":"Bettati","sequence":"additional","affiliation":[{"name":"Centro Interdipartimentale Biopharmanet-TEC, Universit\u00e0 di Parma, Parco Area delle Scienze 27\/A, 43124 Parma, Italy"},{"name":"Dipartimento di Medicina e Chirurgia, Universit\u00e0 di Parma, Via Gramsci 14, 43126 Parma, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,12,29]]},"reference":[{"key":"ref_1","first-page":"e2948","article-title":"Biochemical measurement of neonatal hypoxia","volume":"54","author":"Plank","year":"2011","journal-title":"JoVE"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"397","DOI":"10.1080\/00015385.2017.1335104","article-title":"Serum allantoin and aminothiols as biomarkers of chronic heart failure","volume":"72","author":"Fournier","year":"2017","journal-title":"Acta Cardiol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1016\/j.cca.2013.06.015","article-title":"Plasma allantoin measurement by isocratic liquid chromatography with tandem mass spectrometry: Method evaluation and application in oxidative stress biomonitoring","volume":"424","author":"Chung","year":"2013","journal-title":"Clin. 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